Question

In ABC, AB=12cm and BC=6.5cm, angle ABC=90 degree. If D is the mid point of AC, find the area of ABD and BCD. What did you observe?

Answer 1

Answer:

In the ΔABC, ∠ABC = 90°.

Since AD = DC, D is the midpoint of AC. So BD is the median.

AB ⊥ BC.

Given AB = 12cm. BC=6.5cm.

Area of ΔABC = 1/2 * base * height

= 1/2 * 6.5 * 12 = 39 cm²

Ar(ΔADB) = 1/2 * Ar(ΔABC) , BD is the median.

= 39/2 = 19.5 cm²