The base of a right-angled triangle is 9 cm and its hypotenuse is 15 cm. What is its area?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 54 cm2
The height is the third side, found by Pythagoras: height \(=\sqrt{\text{hypotenuse}^2-\text{base}^2}\). Then area \(=\frac{1}{2}\times\) base \(\times\) height.
Height \(=\sqrt{15^2-9^2}=\sqrt{225-81}=\sqrt{144}=12\) cm
Area \(=\displaystyle\frac{1}{2}\times9\times12=54\) cm2
