Find the area of the quadrilateral (in sq.units) as shown in the figure below. ∠EAB = ∠AED = 90°. Given that: AB + AE = 4 units and EC = 7 units.
Drop BD⊥EC.
Realise that △BDC is a right angled triangle and so we need not use Heron's formula.
So, area of (△BDC) = 12 × BD × DC = 12 × 4 × 3 = 6 square units.
Area of (ABDE) = 42 = 16 square units.
So, area = 16 + 6 = 22 square units.