Set 4: Triangles (Intermediate)

**Choice D is the best answer.** Each side = 21 / 3 = 7

Explanation

Answer: D

PROBLEM

An equilateral triangle has a perimeter of 21. What is the length of each side?

A.

4

B.

10

C.

9

D.

7

✓ Correct

Detailed Explanation

Choice D is the best answer. Each side = 21 / 3 = 7

Why others are wrong:

A: 4 is incorrect because it does not satisfy the equation.

B: 10 is incorrect because it does not satisfy the equation.

C: 9 is incorrect because it does not satisfy the equation.