Question

The breadth of a rectangle is 5 cm each of its diagonals are 13 cm, find its length

Answer 1

A ____ C
|\13cm|
| \ |
| \ |
| \ |
| \ |
|____\|
B 5 cm D

Here breath of rectangle ABCD= BD=5cm and diagonal of rectangle ABCD=AD=13cm
to find the length of rectangle=AB=?
also the mesuare of all of rectangle is 90°

In triangle ABD
triangle ABD=90°
therefore triangle ABD is right angled triangle
by pythagoras theorem
AD^2=AB^2+BD^2
13^2 =AB^2+ 5^2
169 =AB^2+25
AB^2=169 - 25
AB^2= 144
by taking square root
AB= under root 144
AB= 12cm
therefore length of rectangle ABCD is 12cm