Question

Find the length diagonal of a rectangle whose length is 35 cm and breadth is 12 cm.

Answer 1

${\displaystyle \square }$ABCD is a rectangle
${\displaystyle l\left(AB\right)=35cm}$
${\displaystyle l\left(BC\right)=12cm}$

Let AC be the diagonal of rectangle

as  ∠A =  ∠B = ∠C =  ∠D = 90°

∴ In ${\displaystyle △}$ABC, as  ∠B = 90°

∴ By using Pythagoras theorem.

${\displaystyle A{C}^2=A{B}^2+B{C}^2}$
${\displaystyle A{C}^2={35}^2+{12}^2}$
${\displaystyle A{C}^2=1225+144}$
${\displaystyle A{C}^2=1369}$
${\displaystyle AC=37cm}$

∴ The diagonal of the rectangle is 37 cm.