Question

Find the side length of an equilateral triangle whose perimeter is 9 cm.

• A. 9 cm
• B. 81 cm
• C. 6 cm
• D. 3 cm

Answer 1

The correct option is D

3 cm

An equilateral triangle is a triangle in which all three sides are equal.

Perimeter of an equilateral triangle = 3 x length of a side
Let the length of one side of the triangle be 'a'.
$\therefore$ Perimeter of an equilateral triangle = 3a
Given, perimeter of the trianle is 9 cm i.e. 3a = 9
$\therefore a=\frac{9}{3}=3cm$
$\therefore$ Length of one side of the given equilateral triangle = 3 cm.