Atriangle can have at most how many right angle?

Only one (1).

If it had two right angles, they would add up to 180 degrees, and there would be no more degrees left over to make the third angle with.

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

laticia draws the diagram below to show earth’s magnetic field.

answer

the arrows to the right of earth should point up.