Parts of a Triangle: Identifying and defining elements

To determine if a triangle can have a right angle, consider the following explanation:

• Definition of a Right Angle: An angle is classified as a right angle if it measures exactly $90^\circ$.
• Definition of a Right Triangle: A right triangle is a type of triangle that contains exactly one right angle.
• According to the definition, a right triangle specifically includes a right angle. This is a well-established classification of triangles in geometry.

Thus, a triangle can indeed have a right angle and is referred to as a right triangle.

Therefore, the solution to the problem is Yes.

The triangle's altitude is a line drawn from a vertex perpendicular to the opposite side. The vertical line in the diagram extends from the triangle's top vertex straight down to its base. By definition of altitude, this line is the height if it forms a right angle with the base.

To solve this problem, we'll verify that the line in question satisfies the altitude condition:

• Step 1: Identify the triangle's vertices and base. From the diagram, the base appears horizontal, and the vertex lies directly above it.
• Step 2: Check the nature of the line. The line is vertical when the base is horizontal, indicating perpendicularity.
• Conclusion: The vertical line forms right angles with the base, thus acting as the altitude or height.

Therefore, the straight line depicted is indeed the height of the triangle. The answer is Yes.

To determine if the straight line is the height of the triangle, we'll analyze its role within the triangle:

• Step 1: Observe the triangle and the given line. The triangle seems to be made of three sides and a vertical line within it.
• Step 2: Recall that the height of a triangle, in geometry, is defined as a perpendicular dropped from a vertex to the opposite side.
• Step 3: Examine the positioning of the line: The vertical line starts at one vertex of the triangle and intersects the base, appearing to be perpendicular.
• Step 4: Verify perpendicularity: Given that the line is shown as a clear vertical (and a small perpendicular indicator suggests perpendicularity), we accept this line as the height.
• Step 5: Conclude with verification that the line is effectively meeting the definition of height for the triangle in the diagram.

Therefore, the vertical line in the figure is indeed the height of the triangle.

Yes

To determine whether a plane angle can be found in a triangle, we need to understand what a plane angle is and compare it to the angles within a triangle.

• A plane angle is an angle formed by two lines lying in the same plane.
• In the context of geometry, angles found within a triangle are the interior angles, which are the angles between the sides of the triangle.
• Although the angles in a triangle are indeed contained within a plane (since a triangle itself is a planar figure), when referencing "plane angles" in geometry, we usually consider angles related to different geometric configurations beyond those specifically internal to defined planar shapes like a triangle.
• The term "plane angle" typically refers to the measurement of an angle in radians or degrees within a plane, but this doesn't specifically pertain to angles of a triangle.

Therefore, based on the context and usual geometric conventions, the concept of a "plane angle" is not typically used to describe the angles found within a triangle. Thus, a plane angle as defined generally in geometry is not found specifically within a triangle.

Therefore, the correct answer to the question is $\text{No}$.

In the given problem, we have a triangle depicted with a specific line drawn inside it. The question asks if this line represents the height of the triangle. To resolve this question, we need to discern whether the line is perpendicular to one of the sides of the triangle when extended, as only a line that is perpendicular from a vertex to its opposite side can be considered the height.

The line in question is shown intersecting one of the sides within the triangle but does not form a perpendicular angle with any side shown or the ground (as is required for it to be the height of the triangle). A proper height would typically intersect perpendicularly either at or along the extended line of the opposite side from a vertex.

Therefore, based on the visual clues provided and the typical geometric definition of a height (or altitude) in a triangle, this specific line does not fit the criteria for being a height.

Thus, we conclude that the line depicted is not the height of the triangle. The correct answer is No.

To determine if the given straight line is the height of the triangle, we need to check whether it is perpendicular to the side it intersects (or its extension), which is the definition of a height (altitude) in a triangle.

Looking at the figure, the straight line is drawn from a vertex of the triangle to a point on the opposite side, but it is not perpendicular to that side or its extension. Therefore, the line does not meet the criteria for being a height of the triangle.

In conclusion, the line is not the height of the triangle because it is not perpendicular to the opposite side.

Therefore, the correct answer to the problem is No.

To determine if the given line in the triangle is the height, we need to check if it satisfies the conditions of a triangle's altitude.

• Step 1: Identify the base of the triangle. The problem suggests that the horizontal line, presumably at the bottom of the triangle, acts as the base.
• Step 2: The altitude must be drawn from the vertex opposite to the base and be perpendicular to this base. Thus, the potential altitude would start at the apex of the triangle.
• Step 3: The given figure features a straight line connecting two points on the interior of the triangle and is not perpendicular to the base.

Therefore, this line cannot be the height because it does not extend perpendicularly from the apex opposite the base to the base itself.

Thus, the correct answer is No.

To determine if the straight line in the figure is the height of the triangle, we must verify whether it is perpendicular to the base of that triangle.

The height (or altitude) of a triangle is defined as a line segment from a vertex perpendicular to the line containing the opposite side (often referred to as the base).

Upon examining the figure, we see a triangle and a straight line drawn from one vertex towards the opposite side. However, there is no indication or mark suggesting that this line is perpendicular to the base.

Without explicit evidence of perpendicularity, such as a right-angle marking, we cannot assume that the line is the height of the triangle.

Thus, based on the geometric principles related to altitudes in triangles, we conclude the solution to the problem:

No, the straight line in the figure is not the height of the triangle.

The height of a triangle is defined as the perpendicular distance from a vertex to the line containing the opposite side (base). In this problem, we observe a vertical line segment drawn from a point on the base (horizontal line at the bottom of the triangle) to some level above the base. To determine if this line is a height, it must be perpendicular to the base and also reach to the opposite vertex of the triangle.

In the provided figure, the vertical line extends vertically from the base but does not connect to the opposite vertex of the triangle (at the top). Instead, it terminates at some intermediate point above the base. Since the line does not satisfy the full condition of being perpendicular and reaching an opposite vertex, it cannot be considered the height of this triangle.

Therefore, the given straight line is not the height of the triangle.

The correct and final answer is: No.

In geometry, the distance or length of a line segment between two points is the same, regardless of the direction in which it is measured. Consequently, the segments denoted by $BC$ and $CB$ refer to the same segment, both indicating the distance between points B and C.

Hence, the statement "BC = CB" is indeed True.

To solve this problem, we must analyze the provided geometric diagram carefully. The goal is to determine if line segment DE is a side of triangle BDC.

Let's examine the elements in the diagram:

• Triangle BDC is outlined with vertices B, D, and C.
• There is a line connecting points D and E, which does not coincide with the triangle's perimeter as sides are supposed to.
• A clear check shows us that sides BDC are formed by line segments BD, DC, and CB in the triangle.
• The line DE appears as an extension inside or outside of the triangle, making a clear indication that it is not part of the triangle itself.

Given the definition of a triangle's sides enclosed by its three vertices and the connectivity presented, it is apparent that DE is not recognized as one of the edges or sides that enclose triangle BDC.

Hence, the conclusion is: The statement "DE is a side in the triangle BDC" is Not true.

In order to solve this problem, we need to understand the basic properties of an isosceles triangle.

An isosceles triangle has two sides that are equal in length, often referred to as the "legs" of the triangle. The angle formed between these two equal sides, which are sometimes referred to as the "sides", is called the "vertex angle" or sometimes more colloquially as the "main angle".

When considering the vocabulary of the given multiple-choice answers, choice 2: $sides, main$ accurately fills the blanks, as the angle formed between the two equal sides can indeed be referred to as the "main angle".

Therefore, the correct answer to the problem is: $sides, main$.

Let us determine whether $DB$ is a side of triangle $ABC$. This verification depends greatly on understanding the arrangement and positioning of the points given within the triangle.

From the diagram, points $A$, $B$, and $C$ form a triangle because they create a closed figure with three lines connecting one another, typical of triangle sides. On examining point $D$ and the line $DB$, we notice that $D$ seems to be an internal point, potentially serving roles like that of a median or an angle bisector, but not forming an external side of triangle $ABC$.

Based on this understanding, line $DB$ fails to fulfil the requirement of connecting two of the vertices of the triangle directly. Hence, it's internal and is not counted as an external side of triangle $ABC$.

The conclusion based on the given options from the prompt: $DB$ is not a side of triangle $ABC$.

The problem asks us to confirm if AB is a side of triangle ADB.

Triangle ADB is defined by its vertices, A, D, and B. A triangle is formed when three vertices are connected by three sides.

• Identify vertices: The vertices of the triangle are A, D, and B.
• Identify sides: The triangle's sides should be AB, BD, and DA.
• Observe: From the provided diagram, AB connects vertices A and B.

Therefore, based on the definition of a triangle and observing the connection between components, side AB indeed is a part of triangle ADB.

This confirms that the statement is True.

Since line segment DE does not correspond to a full side of any of the triangles present within the given geometry, we conclude that the statement “DE is a side in one of the triangles” is Not true.

To solve the problem of determining whether DE is not a side in any of the triangles, we will methodically identify the triangles present in the diagram and examine their sides:

• Identify triangles in the diagram. The diagram presented forms a right-angled triangle ABC with additional lines forming smaller triangles within.
• Triangles formed: Triangle ABC (major triangle), Triangle ABD, Triangle BEC, and Triangle DBE.
• Let's examine the sides of these triangles:
• Triangle ABC has sides AB, BC, and CA.
• Triangle ABD has sides AB, BD, and DA.
• Triangle BEC has sides BE, EC, and CB.
• Triangle DBE has sides DB, BE, and ED.
• Notice that while point D is used, the segment DE is only part of line BE and isn't listed as a direct side of any triangle.

Therefore, the claim that DE is not a side in any of the triangles is indeed correct.

Hence, the answer is True.

The sum of angles in a triangle is 180 degrees. Since two angles of 90 degrees equal 180, a triangle can never have two right angles.

To determine if $EB$ is a side of either triangle, follow these steps:

• **Step 1:** Identify the vertices of the two triangles as shown in the diagram.
• **Step 2:** The first triangle has vertices $A$, $B$, and $C$. Hence, its sides are $AB$, $BC$, and $CA$.
• **Step 3:** The second triangle has vertices $D$, $E$, and $F$. Therefore, its sides are $DE$, $EF$, and $FD$.
• **Step 4:** Check if $EB$ is one of these sides.

On examining the sides listed for both triangles:

- For triangle $ABC$, we have sides $AB$, $BC$, and $CA$.

- For triangle $DEF$, we have sides $DE$, $EF$, and $FD$.

Clearly, $EB$ is not a side of either triangle.

Therefore, the solution to the problem is No, $EB$ is not a side of one of the triangles.

To solve this problem, we must determine whether the dashed line in the presented triangle fulfills the criteria of being a height. Let's verify each critical aspect:

• First, identify what a height (altitude) is: It is a line drawn from a vertex perpendicular to the opposite side.
• Next, observe the figure. We have a triangle with a dash line drawn from the top vertex to a side that seems to extend from one corner of the base to another point on the extended base.
• Since this line is not shown to be perpendicular to the base of the triangle (no right angle box), we cannot affirm that it fulfills our requirement.

As a result, the straight line does not meet the standard definition of a height for this triangle since it does not form the necessary 90-degree angle with the base. Therefore, as the line is not perpendicular to the opposite side, it is not the height.

Thus, the correct answer to the problem is No.

To determine whether the given line is the height of the triangle, we start by understanding what defines the height of a triangle. The height, or altitude, is a line segment drawn from a vertex perpendicular to the opposite side (the base), forming a right angle with that side.
We need to examine whether the specified line in the diagram is indeed perpendicular to the base of the triangle. If the line is not perpendicular, then it cannot be considered the height.

Upon examining the triangle in the SVG diagram, observe the following:

• The triangle, represented by vertices and sides, has a particular orientation.
• The line in question is drawn from one vertex to another interior point or appears in the interior of the triangle.
• Perpendicularity, if not explicitly shown by a right-angle marker, can also be evaluated by look or guided by other geometrical cues.
• In this case, the line does not appear to be perpendicular to any side explicitly. Usually, height serves as intersection at 90 degrees.

Since the line does not form a 90-degree angle with the triangle's base as determined upon inspection, it is not the height. Therefore, the correct conclusion is that the line shown is not the height of the triangle.

Therefore, the correct answer is: No.