True or false all rhombuses are rectangles true or false

False. A rhombus is a rectangle only if it has a right angle in it.

If a rhombus has a right angle, then all of its angles are right angles.

In that case, it's not only a rectangle, but if you were to look at it,

you would swear you were looking at a square.

(A square is also a rhombus, and it's also rectangle.)