The base of a right pyramid is an equilateral triangle with area 16√3 cm2. If the area of one of its lateral faces is 30 cm2 then its height (in cm ) is?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option is 1 i.e. √611/12
Base = Equilateral triangle
Area = 16√3 cm²
r = a/2√3 = 8/2√3 = 4/√3
Now
h2 + r2 = l2
⇒ h2 = l2 - r2
⇒ h2 = 225/4 - 16/3 = 611/3
⇒ h = √(611/3)