Square, rectangle and a right angle triangle are examples.
square
Lots of objects do not have supplementary angles. It does them, or their environment, no harm.
half of a clock
A rhombus
A ramp, hill
Prefices are used to indicate the number of sides, angles, faces or solid angles (in 3d objects).
Vertical angles are used in construction, computer design, and just about any other field where objects are built. Angles add design and strength.
Squares have 4 rights angles but a rhombus may or may not have 4 right angles.
cubism
There are infinitely many such shapes.
square
They are both 2 dimensional objects with five straight sides and five angles. The sum of the internal angles is 540 degrees, the sum of the exterior angles is 360 degrees.