Right Triangle

🏆Practice types of triangles

Definition of a right triangle

A right triangle is a triangle that has one right angle, meaning an angle of 90 degrees. Based on the fact that the sum of angles in any triangle is 180 degrees, we can conclude that the sum of the two remaining angles in a right triangle is 90 degrees. This means that both angles must be acute (less than 90 degrees).

Right Triangle

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Test yourself on types of triangles!

einstein

Is the triangle in the drawing a right triangle?

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Here are some examples of right triangles:

Examples of right triangles

Exercise

For example, let's take any right triangle. It is known that one of the angles in this triangle is 45 degrees. We are asked to find the second acute angle in the given triangle.

Since this is a right triangle, meaning one of the angles equals 90 degrees, we can calculate and find that the second acute angle will be equal to 45 degrees. Why? Because it complements the first given acute angle to 90 degrees.

Diagram of a right triangle labeled with angles: B = 90°, C = 45°, and A = ?. The triangle illustrates a problem-solving exercise to determine the missing angle A using the triangle sum theorem. Featured in a tutorial on understanding angles in a right triangle.

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Examples with solutions for Types of Triangles

Exercise #1

Is the triangle in the drawing a right triangle?

Step-by-Step Solution

Due to the presence of the 90 degree angle symbol we can determine that this is indeed a right-angled triangle.

Answer

Yes

Exercise #2

Choose the appropriate triangle according to the following:

Angle B equals 90 degrees.

Video Solution

Step-by-Step Solution

Let's note in which of the triangles angle B forms a right angle, meaning an angle of 90 degrees.

In answers C+D, we can see that angle B is smaller than 90 degrees.

In answer A, it is equal to 90 degrees.

Answer

AAABBBCCC

Exercise #3

Given the values of the sides of a triangle, is it a triangle with different sides?

9.19.19.19.59.59.5AAABBBCCC9

Video Solution

Step-by-Step Solution

As is known, a scalene triangle is a triangle in which each side has a different length.

According to the given information, this is indeed a triangle where each side has a different length.

Answer

Yes

Exercise #4

What kid of triangle is given in the drawing?

90°90°90°AAABBBCCC

Video Solution

Step-by-Step Solution

The measure of angle C is 90°, therefore it is a right angle.

If one of the angles of the triangle is right, it is a right triangle.

Answer

Right triangle

Exercise #5

What kind of triangle is given in the drawing?

999555999AAABBBCCC

Video Solution

Step-by-Step Solution

Given that sides AB and AC are both equal to 9, which means that the legs of the triangle are equal and the base BC is equal to 5,

Therefore, the triangle is isosceles.

Answer

Isosceles triangle

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