The area of an equilateral triangle is 81√3 square cm. Find its side and altitude.
Show answer & explanation
Correct answer: B
Explanation
Area of equilateral triangle = 81√3 cm²
Area = (√3/4) × a²
Elevation = (√3/2) × a
(√3/4) × a² = 81√3
a² / 4 = 81
a² = 324
a = 18
Altitude= (√3/2) × 18= 9√3
side = 18 cm
Altitude = 9√3 cm