Question

Work out the area of triangle ABC.
B.
25 cm
A
32 cm
D
2 cm

Answer 1

Explanation:

ΔADB is a right angled triangle. So, use Pythagorean theorem.

Altitude² = hypotenuse² - base²

= (2√5)² - (3√2)²

= 2²* (√5)² - 3²*(√2)² = 4*5 - 9*2 = 20 - 18 = 2

Altitude = √2

Base of ΔABC = 3√2 + √2 = 4√2 cm

Area =
`(1)/(2)bh`

`= (1)/(2)*4√(2)*√(2)\\\\\\=(1)/(2)*4*√(2*2)\\\\\\=(1)/(2)*4*2\\\\= 4 cm^(2)`