How to calculate the area of a triangle using trigonometry?
Throughout geometry studies, which deal with various structures and shapes, you are required to calculate areas and perimeters. Each shape or structure has a different formula through which you can answer the question and calculate the area. Fortunately, there is one formula that can be applied to all triangles, and it can be used to calculate the area of a triangle using trigonometry.
In the field of mathematics, emphasis is also placed on trigonometry, which deals with the study of triangles, their angles, and sides. Every student is required to demonstrate knowledge of triangles (from right triangles to isosceles triangles), and thus also answer the question of how to calculate the area of a triangle using trigonometry.
One formula for all different triangles
Now that you know the formula for calculating the area of a triangle using trigonometry, you can use it in any question where you need to calculate areas in triangles. The formula for calculating the triangle:
Calculate the area of the triangle using the data in the figure below.
Incorrect
Correct Answer:
14
Question 5
Calculate the area of the triangle using the data in the figure below.
Incorrect
Correct Answer:
24
Examples with solutions for Area of a Triangle
Exercise #1
What is the area of the given triangle?
Video Solution
Step-by-Step Solution
This question is a bit confusing. We need start by identifying which parts of the data are relevant to us.
Remember the formula for the area of a triangle:
The height is a straight line that comes out of an angle and forms a right angle with the opposite side.
In the drawing we have a height of 6.
It goes down to the opposite side whose length is 5.
And therefore, these are the data points that we will use.
We replace in the formula:
26Ć5ā=230ā=15
Answer
15
Exercise #2
What is the area of the triangle in the drawing?
Video Solution
Step-by-Step Solution
First, we will identify the data points we need to be able to find the area of the triangle.
the formula for the area of the triangle: height*opposite side / 2
Since it is a right triangle, we know that the straight sides are actually also the heights between each other, that is, the side that measures 5 and the side that measures 7.
We multiply the legs and divide by 2
25Ć7ā=235ā=17.5
Answer
17.5
Exercise #3
The triangle ABC is given below. AC = 10 cm
AD = 3 cm
BC = 11.6 cm What is the area of the triangle?
Video Solution
Step-by-Step Solution
The triangle we are looking at is the large triangle - ABC
The triangle is formed by three sides AB, BC, and CA.
Now let's remember what we need for the calculation of a triangular area:
(side x the height that descends from the side)/2
Therefore, the first thing we must find is a suitable height and side.
We are given the side AC, but there is no descending height, so it is not useful to us.
The side AB is not given,
And so we are left with the side BC, which is given.
From the side BC descends the height AD (the two form a 90-degree angle).
It can be argued that BC is also a height, but if we delve deeper it seems that CD can be a height in the triangle ADC,
and BD is a height in the triangle ADB (both are the sides of a right triangle, therefore they are the height and the side).
As we do not know if the triangle is isosceles or not, it is also not possible to know if CD=DB, or what their ratio is, and this theory fails.
Let's remember again the formula for triangular area and replace the data we have in the formula:
(side* the height that descends from the side)/2
Now we replace the existing data in this formula:
2CBĆADā
211.6Ć3ā
234.8ā=17.4
Answer
17.4
Exercise #4
Calculate the area of the triangle using the data in the figure below.
Video Solution
Step-by-Step Solution
To solve for the area of a triangle when the base and height are given, we'll use the formula:
Area=21āĆbaseĆheight
Given:
Base = 4 units
Height = 7 units
Apply the formula:
Areaāamp;=21āĆ4Ć7amp;=21āĆ28amp;=14ā
Thus, the area of the triangle is 14 square units.
Answer
14
Exercise #5
Calculate the area of the triangle using the data in the figure below.
Video Solution
Step-by-Step Solution
To find the area of the given triangle, we will follow these steps:
Step 1: Identify the given base and height from the problem.
Step 2: Apply the formula for the area of a triangle.
Step 3: Calculate the area by substituting the values into the formula.
Let's work through the problem:
Step 1: The base ā£AB⣠of the triangle is given as 8 units, and the height ā£BC⣠is 6 units.
Step 2: The formula for the area of a triangle is:
A=21āĆbaseĆheight
Step 3: Substitute the given values into the formula:
A=21āĆ8Ć6
Perform the multiplication:
A=21āĆ48=24
Therefore, the area of the triangle is 24 square units.
Answer
24
Question 1
Calculate the area of the triangle using the data in the figure below.
Incorrect
Correct Answer:
45
Question 2
Calculate the area of the triangle using the data in the figure below.
Incorrect
Correct Answer:
10
Question 3
Calculate the area of the triangle using the data in the figure below.
Incorrect
Correct Answer:
24
Question 4
Complete the sentence:
To find the area of a right triangle, one must multiply ________________ by each other and divide by 2.
Incorrect
Correct Answer:
the two legs
Question 5
Calculate the area of the triangle, if possible.
Incorrect
Correct Answer:
14
Exercise #6
Calculate the area of the triangle using the data in the figure below.
Video Solution
Step-by-Step Solution
To solve this problem, we'll follow these steps:
Step 1: Identify the given information
Step 2: Apply the appropriate formula
Step 3: Perform the necessary calculations
Now, let's work through each step:
Step 1: We are given that AC=9 (the height) and BC=10 (the base) of the triangle.
Step 2: We'll use the formula for the area of a triangle: Area=21āĆbaseĆheight.
Step 3: Plugging in our values, we have:
Area=21āĆ10Ć9=21āĆ90=45.
Therefore, the area of the triangle is 45.
Answer
45
Exercise #7
Calculate the area of the triangle using the data in the figure below.
Video Solution
Step-by-Step Solution
To solve the problem of finding the area of triangle ā³ABC, we follow these steps:
Step 1: Identify the given measurements.
Step 2: Use the appropriate formula for the area of a triangle.
Step 3: Calculate the area using these measurements.
Let's go through each step in detail:
Step 1: From the figure, the base AB=10 and height AC=2.
Step 2: The formula for the area of a triangle is: Area=21āĆbaseĆheight.
Step 3: Substituting the known values into the formula, we get:
Area=21āĆ10Ć2=21āĆ20=10
Therefore, the area of triangle ā³ABC is 10.
Answer
10
Exercise #8
Calculate the area of the triangle using the data in the figure below.
Video Solution
Step-by-Step Solution
To calculate the area of the triangle, we will follow these steps:
Identify the base, CB, as 6 units.
Identify the height, AC, as 8 units.
Apply the area formula for a triangle.
Now, let's work through these steps:
The triangle is a right triangle with base CB=6 units and height AC=8 units.
The area of a triangle is determined using the formula:
Area=21āĆbaseĆheight
Substituting the known values, we have:
Area=21āĆ6Ć8
Perform the multiplication and division:
Area=21āĆ48=24
Therefore, the area of the triangle is 24 square units.
Answer
24
Exercise #9
Complete the sentence:
To find the area of a right triangle, one must multiply ________________ by each other and divide by 2.
Step-by-Step Solution
To solve this problem, begin by identifying the elements involved in calculating the area of a right triangle. In a right triangle, the two sides that form the right angle are known as the legs. These legs act as the base and height of the triangle.
The formula for the area of a triangle is given by:
A=21āĆbaseĆheight
In the case of a right triangle, the base and height are the two legs. Therefore, the process of finding the area involves multiplying the lengths of the two legs together and then dividing the product by 2.
Based on this analysis, the correct way to complete the sentence in the problem is:
To find the area of a right triangle, one must multiply the two legs by each other and divide by 2.
Answer
the two legs
Exercise #10
Calculate the area of the triangle, if possible.
Video Solution
Step-by-Step Solution
To solve this problem, we'll follow these steps:
Step 1: Identify the base and height of the triangle.
Step 2: Substitute these values into the formula for the area of a triangle.
Step 3: Perform the calculation to determine the area.
Let's work through each step:
Step 1: From the given information, the base of the triangle is 7 units, and the height is 4 units.
Step 2: We'll use the formula for the area of a triangle: Area=21āĆbaseĆheight
Step 3: Plugging in the values for the base and height, we have: Area=21āĆ7Ć4
Performing the multiplication, we get: Area=21āĆ28=14
Therefore, the area of the triangle is 14 square units.
Answer
14
Question 1
Calculate the area of the triangle below, if possible.
Incorrect
Correct Answer:
10.5
Question 2
Calculate the area of the triangle below, if possible.
Incorrect
Correct Answer:
Cannot be calculated
Question 3
Calculate the area of the triangle below, if possible.
Incorrect
Correct Answer:
It cannot be calculated.
Question 4
Calculate the area of the triangle below, if possible.
Incorrect
Correct Answer:
17.5
Question 5
Calculate the area of the triangle below, if possible.
Incorrect
Correct Answer:
14
Exercise #11
Calculate the area of the triangle below, if possible.
Video Solution
Step-by-Step Solution
To solve this problem, we will determine the area of the triangle using the given base and height. Here are the steps:
Identify the given base and height: base =6, height =3.5.
Apply the formula for the area of a triangle: Area=21āĆbaseĆheight.
Substitute the given values into the formula: Area=21āĆ6Ć3.5.
Calculate the area: =21āĆ21=10.5.
Therefore, the area of the triangle is 10.5, which matches the correct multiple-choice option provided.
Answer
10.5
Exercise #12
Calculate the area of the triangle below, if possible.
Video Solution
Step-by-Step Solution
The formula to calculate the area of a triangle is:
(side * height corresponding to the side) / 2
Note that in the triangle provided to us, we have the length of the side but not the height.
That is, we do not have enough data to perform the calculation.
Answer
Cannot be calculated
Exercise #13
Calculate the area of the triangle below, if possible.
Video Solution
Step-by-Step Solution
To solve this problem, we begin by analyzing the given triangle in the diagram:
While the triangle graphic suggests some line segments labeled with the values "7.6" and "4", it does not confirm these as directly usable as pure base or height without additional proven inter-contextual relationships establishing perpendicularity or side/unit equivalences.
Without a clear base and perpendicular height value, we cannot apply the triangle's area formula Area=21āĆbaseĆheight effectively, nor do we have all side lengths for Heron's formula.
Therefore, due to insufficient information that specifically identifies necessary dimensions for area calculations such as clear height to a base or all sides' measures, the area of this triangle cannot be calculated.
The correct answer to the problem, based on insufficient explicit calculable details, is: It cannot be calculated.
Answer
It cannot be calculated.
Exercise #14
Calculate the area of the triangle below, if possible.
Video Solution
Step-by-Step Solution
To solve this problem, we'll follow these steps:
Step 1: Identify the given base and height of the triangle.
Step 2: Apply the formula for the area of a triangle.
Step 3: Perform the necessary calculations to find the area.
Now, let's work through each step:
Step 1: The base of the triangle is given as 7 units, and the height is given as 5 units.
Step 2: We'll use the formula for the area of a triangle: Area=21āĆbaseĆheight.
Step 3: Plugging in our values, we have: Area=21āĆ7Ć5=21āĆ35=17.5.
Therefore, the area of the triangle is 17.5 square units.
Answer
17.5
Exercise #15
Calculate the area of the triangle below, if possible.
Video Solution
Step-by-Step Solution
To solve this problem, we will follow these steps:
Step 1: Identify the relevant sides based on problem context
Step 2: Apply the standard triangle area formula
Step 3: Calculate the area based on the known values for base and height
Let's work through each step in detail:
Step 1: We are seeking to calculate the area of the triangle. We identified that the line segment of 4 units represents the height, and the base is 7 units.
Step 2: We will apply the formula for the area of a right triangle: Area=21āĆbaseĆheight.
Step 3: Plug the values we have: Area=21āĆ7Ć4=21āĆ28=14.
Thus, the area of the triangle is 14 square units.