Question

Example 1 : Show that each angle of a rectangle is a right angle.
al
et us recall what a rectangle is.​

Answer 1

Explanation:

Let, ABCD be a rectangle.

We have to prove that ∠A=∠B=∠C=∠D=90o

We know that a rectangle is parallelogram where its one angle is 90o.

Let us assume ∠A=90o

Now, 

AD∥BC[oppositesidesofaparallelogramareparallel]

And AB is transversal.

So, ∠A+∠B=1800[interioranglesonthwsamwsideofatransversalaresupplementary]⇒90o+∠B=1800⇒∠B=90o

Again, we know that opposite angles of a parallelogram are equal.

∴∠C=∠A and ∠D=∠B

∴∠C=90o and ∠D=90o

∴∠A=∠B=∠C=∠D=90o

Hence, it is proved that ABCD is a rectangle.

Answer 2

Answer:

thanks for points......