How many right angles does a right triangle contain?

Answer 1

A Right Angle Triangle contains one right angle.

A right angle has a magnitude of 90°, or in radians (pi/2). A triangle has three angles forming the closed shape, the addition of which gives an angle of 180°, or pi radians. With two right angles, the addition of these alone gives 180° (pi radians), and therefore the last angle has a null value. This is impossible and therefore leads to the conclusion that no triangle can have more then one right angle.

As the definition of a Right Angle Triangle requires an angle of 90°, and no triangle can have two of these angles a Right Angle Triangle must have exactly one right angle.