Area of Equilateral Triangle Practice Problems & Solutions

Master calculating equilateral triangle area with step-by-step practice problems. Learn to use height, median, and bisector properties in triangle geometry.

📚Practice Calculating Equilateral Triangle Area Step-by-Step
  • Apply the area formula for equilateral triangles using base and height
  • Identify when median, height, and bisector are the same in equilateral triangles
  • Solve problems using equal side lengths in equilateral triangles
  • Calculate area when given different measurements like median or bisector
  • Work through multi-step problems involving triangle properties
  • Master both basic and advanced equilateral triangle area calculations

Understanding Area of Equilateral Triangles

Complete explanation with examples

Formula to calculate the area of an equilateral triangle:

A - Formula for area of equilateral triangle

Detailed explanation

Practice Area of Equilateral Triangles

Test your knowledge with 27 quizzes

Calculate the area of the following triangle:

666777AAABBBCCCEEE

Examples with solutions for Area of Equilateral Triangles

Step-by-step solutions included
Exercise #1

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=12×base×height A = \frac{1}{2} \times \text{base} \times \text{height}

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 #2

Calculate the area of the following triangle:

444555AAABBBCCCEEE

Step-by-Step Solution

The formula for calculating the area of a triangle is:

(the side * the height from the side down to the base) /2

That is:

BC×AE2 \frac{BC\times AE}{2}

We insert the existing data as shown below:

4×52=202=10 \frac{4\times5}{2}=\frac{20}{2}=10

Answer:

10

Video Solution
Exercise #3

Calculate the area of the triangle using the data in the figure below.

101010222AAABBBCCC

Step-by-Step Solution

To solve the problem of finding the area of triangle ABC \triangle ABC , 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 AB = 10 and height AC=2 AC = 2 .
Step 2: The formula for the area of a triangle is: Area=12×base×height \text{Area} = \frac{1}{2} \times \text{base} \times \text{height} .
Step 3: Substituting the known values into the formula, we get:

Area=12×10×2=12×20=10 \text{Area} = \frac{1}{2} \times 10 \times 2 = \frac{1}{2} \times 20 = 10

Therefore, the area of triangle ABC \triangle ABC is 10.

Answer:

10

Video Solution
Exercise #4

Calculate the area of the triangle using the data in the figure below.

444777AAABBBCCC8.06

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=12×base×height \text{Area} = \frac{1}{2} \times \text{base} \times \text{height}

Given:

  • Base = 44 units

  • Height = 77 units

Apply the formula:

Area=12×4×7=12×28=14 \begin{aligned} \text{Area} &= \frac{1}{2} \times 4 \times 7 \\ &= \frac{1}{2} \times 28 \\ &= 14 \end{aligned}

Thus, the area of the triangle is 1414 square units.

Answer:

14

Video Solution
Exercise #5

Calculate the area of the following triangle:

4.54.54.5777AAABBBCCCEEE

Step-by-Step Solution

To find the area of the triangle, we will use the formula for the area of a triangle:

Area=12×base×height \text{Area} = \frac{1}{2} \times \text{base} \times \text{height}

From the problem:

  • The length of the base BC BC is given as 7 units.
  • The height from point A A perpendicular to the base BC BC is given as 4.5 units.

Substitute the given values into the area formula:

Area=12×7×4.5 \text{Area} = \frac{1}{2} \times 7 \times 4.5

Calculate the expression step-by-step:

Area=12×31.5 \text{Area} = \frac{1}{2} \times 31.5

Area=15.75 \text{Area} = 15.75

Therefore, the area of the triangle is 15.75 15.75 square units. This corresponds to the given choice: 15.75 15.75 .

Answer:

15.75

Video Solution

Frequently Asked Questions

What is the formula for the area of an equilateral triangle?

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The area of an equilateral triangle is calculated using the formula: Area = (base × height) ÷ 2. Since all sides are equal in an equilateral triangle, you can use any side as the base and find the corresponding height.

How do you find the height of an equilateral triangle?

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In an equilateral triangle, the height can be found using the formula h = (√3/2) × side length. Alternatively, if you know the area and base, you can rearrange the area formula: height = (2 × area) ÷ base.

Why are height, median, and bisector the same in equilateral triangles?

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In equilateral triangles, all sides and angles are equal. This symmetry means that the line from any vertex to the opposite side's midpoint serves as the height (perpendicular), median (divides side in half), and angle bisector (divides angle in half) simultaneously.

What are the steps to solve equilateral triangle area problems?

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Follow these steps: 1) Identify given measurements (side, height, median, or bisector), 2) Remember that median = height = bisector in equilateral triangles, 3) Use the fact that all sides are equal, 4) Apply the area formula: Area = (base × height) ÷ 2, 5) Calculate and include proper units.

How do you solve area problems when only the median is given?

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Since the median equals the height in equilateral triangles, use the median value as the height in your area formula. If you also need the side length, remember that in an equilateral triangle, all sides are equal, so use any given side measurement.

What common mistakes should I avoid when calculating equilateral triangle area?

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Common mistakes include: forgetting that all sides are equal, not recognizing that median = height = bisector, using the wrong formula, forgetting to divide by 2 in the area formula, and not including proper units in the final answer.

Can you calculate equilateral triangle area with just one side length?

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Yes! If you know one side length (s), you can find the area using the special formula: Area = (√3/4) × s². Alternatively, calculate the height using h = (√3/2) × s, then use the standard area formula.

How are equilateral triangle area problems different from other triangles?

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Equilateral triangles have unique properties that simplify calculations: all sides are equal, all angles are 60°, and the height, median, and angle bisector from any vertex are the same line. These properties make many measurements interchangeable in problem-solving.

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