Question

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

Answer 1

$$\begin{gathered} \mathrm{Using}\mathrm{Pythagoras}\mathrm{theorem}: \\ A{D}^2+D{C}^2=A{C}^2 \\ {5}^2+{12}^2=A{C}^2 \\ 25+14=A{C}^2 \\ 169=A{C}^2 \\ AC=\sqrt{169} \\ =13\mathrm{cm} \\ \mathrm{Thus},\mathrm{length}\mathrm{of}\mathrm{the}\mathrm{diagonal}\mathrm{is}13\mathrm{cm}. \end{gathered}$$