Area of polygon ABCDE = Area of right ∆AFB + Area of trapezium BFHC + Area of right ∆CHD + Area of right ∆EGD + Area of right ∆AGE

FH = AH – AF = 6 – 3 = 3 cm.
HD = AD – AH = 8 – 6 = 2 cm.
GD = AD – AG = 8 – 4 = 4 cm.
= 3 + 7.5 + 3 + 5 + 5
= 23.5 cm2