Worksheet: Equilateral Triangles

In this worksheet, we will practice identifying equilateral triangles by their equal side lengths or equal angle measures to find a missing side length, perimeter, or area.

Q1:

Find the perimeter of the shape below.

Q2:

One side of an equaliteral triangle has length . Another side has length . Find the perimeter of the triangle.

Q3:

The perimeter of an equilateral triangle is equal to the perimeter of a rectangle with a length of 5 cm and a width of 4 cm. Find the length of one side of the triangle.

Q4:

Find the perimeter of .

Q5:

In the figure, find the values of and .

Q6:

In the figure below, is an equilateral triangle, , and . Find .

Q7:

The area of an equilateral triangle is cm². Find the side length.

Q8:

The diagram shows an equilateral triangle. Find the length of its sides.

Q9:

What is the ratio of the length of a side of an equilateral triangle to its perimeter?

Q10:

A triangle has three sides equal in length and a perimeter of 24 length units. Find the length of one of its sides.

Q11:

Calculate the length of one of the sides of an equilateral triangle which has a perimeter of 93 m.

Q12:

Given that triangle is equilateral, and , determine the lengths of and .

A60 cm, 60 cm
B120 cm, 120 cm
C120 cm, 240 cm
D240 cm, 240 cm

Q13:

If one of the sides of an equilateral triangle measures 50 cm, calculate its perimeter.

Q14:

If a square with side length 54 cm has the same perimeter as an equilateral triangle, what is the side length of the triangle?

Q15:

Find the value of given is a triangle where .

Q16:

What is the measure of each angle in an equilateral triangle?

Q17:

From a deck of cards that has a length of inches, you take two cards and lean them together to create an equilateral triangle. What is the height of the triangle?

A inches
B inches
C inches
D inches
E inches

Q18:

In , if , then .

Q19:

In , if , then .

Q20:

If the measure of the vertex angle of an isosceles triangle is , then the triangle is .

Aa right-angled triangle
Ba scalene triangle
Can equilateral triangle

Q21:

is a triangle where . Find the value of .

Q22:

In a triangle , if , what is ?

Q23:

Write an equation for the perimeter, cm, of an equilateral triangle with sides of length cm.

Q24:

Find the area of the equilateral triangle whose circumcircle’s equation is .

A square units
B square units
C square units
D square units

Q25:

Write this ratio in its simplest form: The ratio of the side length of an equilateral triangle to its perimeter.