The height of an equilateral triangle is 18 cm. Its area is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 108√3 sq. cm
Suppose the side of equilateral triangle = a cm
Height of the equilateral triangle:
h = 18 cm
⇒ √3a/2 = 18
⇒ a = 12√3 cm
Required Area = √3a2/4
= (√3/4)(12√3)2
= 108√3 cm2