Question

How can an isosceles triangle have a right angle?

Answer 1

If the other two angles are `45^@` each.

Answer 2

There's only one solution to `A=90^circ`, `quad B=C quad` and `A+B+C=180^circ` and that's `B=C=45^circ`, so the `45^circ, 45^circ,90^circ` right triangle is isosceles too.

Explanation:

If people's homework are any indication, you'll spend a whole year of trig studying the `45^circ, 45^circ, 90^circ` triangle and the `30^circ, 60^circ, 90^circ` triangle.