What is the side of equilateral triangle is altitude is 10

11.55

Step-by-step explanation:

An equilateral triangle is one which all it sides are equal.

10cm altitude means the height is 10cm.

Using Pythagoras theorem,

x² = 10² + (x/2) ²

Assume that the side of the triangle is xcm

x² - x²/4 = 100

3x²/4 = 100

x = √ (400/3)

x = 11.55cm