Question

Question 15

Area of $\Delta PQR$ is $100c{m}^2$ as shown in the figure below. If altitude QT is 10 cm, then its base PR is

(a) 20 cm
(b) 15 cm
(c) 10 cm
(d) 5 cm

Answer 1

Given, area of $\Delta PQR=100c{m}^2$
We know that,
Area of a triangle $=\frac{1}{2}\times Base\times Height$
$\therefore Areaof\Delta PQR=\frac{1}{2}\times PR\times QT$
$\Rightarrow 100=\frac{1}{2}\times PR\times 10$ $[\because QT=10cm,given]$
$\Rightarrow PR=\frac{100\times 2}{10}$
$\Rightarrow PR=20cm$