Question

If the length of one side of an equilateral triangle measures 40 cm, what is the length of its altitude? State the letter of the correct answer.

Answer 1

the length of its altitude is 34.64 cm

Explanation:

Given;

length of a side of the equilateral triangle, L = 40 cm

All the sides of an equilateral triangle are equal

To get the altitude of the triangle, draw a perpendicular line from one of the vertices to intersect the opposite side.

Let the altitude = h

half of the opposite side intersected by the altitude = 20 cm

Apply Pythagoras theorem to determine the altitude 'h'

h² = 40² - 20²

h² = 1200

h = √1200

h = 34.64 cm

Therefore, the length of its altitude is 34.64 cm