The perimeter of an equilateral triangle is 60 m. The area is
a. 10√3 m²
b. 15√3 m²
c. 20√3 m²
d. 100√3 m²

Solution:

Given, the perimeter of an equilateral triangle is 60 m.

We have to find the area.

We know that in an equilateral triangle all the sides are equal.

Let the side of the equilateral triangle be a cm.

Perimeter = side + side + side

So, 60 = a + a + a

3a = 60

a = 60/3

a = 20 m

Therefore, the length of the side is 20 m.

Area of an equilateral triangle = √3/4 (side)²

= √3/4 (20)²

= √3/4 (400)

= 100√3 m²

Therefore, the area of equilateral triangle is 100√3 m²

✦ Try This: The perimeter of an equilateral triangle is 40 m. The area is

☛ Also Check: NCERT Solutions for Class 9 Maths Chapter 12

NCERT Exemplar Class 9 Maths Exercise 12.1 Problem 2

The perimeter of an equilateral triangle is 60 m. The area is a. 10√3 m², b. 15√3 m², c. 20√3 m², d. 100√3 m²

Summary:

An Equilateral triangle is a triangle in which all three sides are equal and angles are also equal. The perimeter of an equilateral triangle is 60 m. The area is 100√3 m²

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