Question

in triangle abc, angle abc equal to 90 degrees,ad= equal to DC, a b equal to 12 cm and BC equal to 6.5 cm find the area of adb

Answer 1

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