How Can A Triangle Have Three Right Angles?

It is not contained in one plane. Such a triangle can be formed on the surface of a sphere, and perhaps in an infinite number of other curved spaces. Consider, for example, the triangle bounded by
 - the Prime Meridian
 - 90^o W longitude
 - the equator.

It can't.  The sum of the angles in a triangle is always 180.  Three right angles would make the sum 270.  It can't even have two right angles.

Oddman is right.  Most people know only Euclidean geometry.

Watch this video.  No trickery, just non-Euclidean geometry.  Imagine the ball in the video is the planet.

www.metacafe.com

Try draw a triangle on the ball

A radius of a circle meets the circumference at a right angle.
If we have another radius at right angles to the first and include the quarter circle of the circumference, we have a triangle with three right angles, albeit with 1 curved side. As the radius of the circle gets larger, the curve of the circumference gets more like a straight line so at infinite radius the triangle exists.
Bit of a problem at infinity because circumference is 2 x Pi x radius so third side would be 1/4 x 2 x Pi x radius or just over 1 1/2 x radius. BUt radius is infinite so this bit can't be longer can it?.

Don't you just love maths!

This is  a trick question because a right angle is 90 degrees so there is no way a triangle can have three right angles. The sum of all the angles of a triangle is always 180 degrees so there is no way you can make that out of three right angles without going over limit.

a triangle never has 3 right angle 3 Right total comes 270 triangle only carries 180 degree through out the world

It can't, however there is such thing as a right triangle, which only has one right angle.