Question

The area of triangle PQR is $ 100 c{m}^{2}$ (figure). 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

We know that, the area of the triangle $=\frac{1}{2}$ $\times$ base$\times$ height

From the given details we note that,

Area of triangle PQR $=100c{m}^2$

Height of the triangle $=$ $10cm$ $=$ altitude

Therefore, the area of triangle $=$ $\frac{1}{2}$$\times$ base $\times$ height

$100=\frac{1}{2}\times$PR$\times$$10$

PR$=$$\frac{100\times 2}{10}$

PR$=$$\frac{200}{10}$

PR$=$$20$

Therefore, the base of triangle( PR) $=$$20$