Question

How to prove that each angle of a rectangle is 90 degree

Answer 1

Given : A rectangle ABCD

to prove : angle A =
angle B =
angle C =
angle D = 90 degree

proof :

we know that

rectangle is a parallelogram where one angle is 90 degree.

hence; lets assume
angle A = 90 degree

Now
AB || BC
( opposite sides of parallelogram are parallel)

and AB is a transversal

So, angle A+ angle B = 180 degree
( interior angle on the same side of transversal are supplementary)

I hope it's help you.....

thx ✌

Answer 2

Opposite sides are parallel and it has at least 1 90 degree angle (A right paralleogram)

It has 3 90 degree angles - then the fourth one must also be 90 degrees and it would then be a rectangle

Diagonals of a parallelogram are congruent

It’s a cyclic quadrilateral (It can be inscribed in a circle) and has at least 2 right angles that aren’t opposite another

Opposite sides (1 pair is enough) are equal length and it has at least 1 right angle