Question

What is the height of an isosceles triangle whose base is 10 and whose equal sides are 20?

Answer 1

Height: `5sqrt(15)`

Explanation:

The perpendicular bisector divides the base into segments of length `5` each.

Using the Pythagorean Theorem:
`color(white)("XXX")color(blue)5^2+color(green)h^2=color(red)(20)^2`

`color(white)("XXX")color(green)h=sqrt(color(red)(400)-color(blue)(25))=5sqrt(15)`