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:

888101010AAABBBCCCEEE

Examples with solutions for Area of Equilateral Triangles

Step-by-step solutions included
Exercise #1

Calculate the area of the right triangle below:

101010666888AAACCCBBB

Step-by-Step Solution

Due to the fact that AB is perpendicular to BC and forms a 90-degree angle,

it can be argued that AB is the height of the triangle.

Hence we can calculate the area as follows:

AB×BC2=8×62=482=24 \frac{AB\times BC}{2}=\frac{8\times6}{2}=\frac{48}{2}=24

Answer:

24 cm²

Video Solution
Exercise #2

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
Exercise #3

What is the area of the triangle in the drawing?

5557778.68.68.6

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

5×72=352=17.5 \frac{5\times7}{2}=\frac{35}{2}=17.5

Answer:

17.5

Video Solution
Exercise #4

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

666888AAABBBCCC

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 CB = 6 units and height AC=8 AC = 8 units.

The area of a triangle is determined using the formula:

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

Substituting the known values, we have:

Area=12×6×8 \text{Area} = \frac{1}{2} \times 6 \times 8

Perform the multiplication and division:

Area=12×48=24 \text{Area} = \frac{1}{2} \times 48 = 24

Therefore, the area of the triangle is 24 24 square units.

Answer:

24

Video Solution
Exercise #5

Calculate the area of the triangle below, if possible.

7.67.67.6444

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

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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