Question

Area of triangle PQR is 100 cm² as shown in the below figure. If altitude QT is 10 cm, then its base PR is ______.

Options

• 20 cm

• 15 cm

• 10 cm

• 5 cm

Answer 1

Area of triangle PQR is 100 cm² as shown in the below figure. If altitude QT is 10 cm, then its base PR is 20 cm.

Explanation:

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

From the question, it is given that, area of triangle PQR = 100 cm²

Height of the triangle = 10 cm = altitude

Therefore, area of triangle = ${\displaystyle \frac{1}{2}}$ × base × height

100 = ${\displaystyle \frac{1}{2}}$ × PR × 10

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

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

PR = 20 cm