Description: Can you build a triangle that is both a right triangle and an isosceles triangle? Created by Sal Khan. But it's also an isosceles triangle, so that means it has to have at least two sides equal and has two sides of length 3. So those two sides that are going to be equal are going to be of length 3, and it's got to be a right triangle. And let's make this side and this side have length 3, so 3 and then 3 right over there.*Teacher Advisor is 100% free.