Question

Find the length of the diagonal of a rectangle whose sides are 12 cm and 5 cm.

Answer 1

In rectangle ABCD, AB= 12 cm and AD = 5 cm

BD is its diagonal
Now, in right angled $\Delta ABD$,
$B{D}^2=A{B}^2+A{D}^2$ (Pythagoras theorem)
$=(12{)}^2+(5{)}^2=144+25=169=(13{)}^2\therefore BD=13cm$
$\therefore$ Length of diagonal = 13 cm