Can you answer this ?

Question

The perimeter of an equilateral triangle is 18. find the measure of the altitude.
-3
-6
-3xSquareroot2
-3xSquareroot3

Answer 1

For an equilateral triangle with side 'a'

Perimeter = 3xa
altitude = ax(squareroot3) /2

Thus perimeter of 18 gives a =6 (6x3 =18)

So altitude = 6x (squareroot3) /2
= 3xSquareroot3
Answer = 3xSquareroot3

Answer 2

Each side of the equiateral triangle is 6 units
The altitude of an equilateral triangle is given by 3sqrt side/2
Hence altitude=3sqrt3 units

Answer 3

All sides are 6
Let altitude = x
6² = 3² + x²
x² = 27
x = 3√3 (last answer)