A child draws the figure of an aeroplane as shown. Here, the wings ABCD and FGHI are parallelograms, the tail DEF is an isosceles triangle, the cockpit CKI is a semicircle and CDFI is a square. In the given figure, BP ⊥ CD, HQ ⊥ FI and EL ⊥ DF. If CD = 8 cm, BP = HQ = 4 cm and DE = EF = 5 cm, find the area of the whole figure. [Take π = 3.14.]
Area of whole figure = ar || ABCD + ar || FGHI + ar DCIF + ar ∆DEF + area semicircle
CD = 8 cm, BP = HQ = 4 cm, DE = EF = 5 cm, CI = 8 cm
ar ∥ ABCD = ar ∥ FGHI = base × height
ar ∥ ABCD = ar ∥ FGHI = BP×DC
ar ∥ ABCD = ar ∥ FGHI = 4×8
ar ∥ ABCD = ar ∥ FGHI = 32 cm2→ eqn1 and eqn2
ar DCIF = area of square = side×side
ar DCIF = DC×CI
ar DCIF = 8×8
ar DCIF = 64 cm2→ eqn3
Consider ∆DEF, EF⊥DF and ∆DEF is isosceles
So, FL = LD
FL = LD = 4 cm
In ∆DEL, ∠DLE = 90°
52 = EL2 + 42 (putting the values)
25 = EL2 + 16
25 – 16 = EL2
⇒ EL2 = 9
∴ EL = 3 cm
⇒ Area of ∆DEF = 4×3
∴ Area of ∆DEF = 12 cm2→ eqn4
R = 4 cm
⇒ Area of semicircle = 3.14×8
∴ Area of semicircle = 25.12 cm2→ eqn5
Area of whole figure = eqn1 + eqn2 + eqn3 + eqn4 + eqn5
⇒ Area of whole figure = 32 + 32 + 64 + 12 + 25.12
∴ Area of whole figure = 165.12 cm2
Area of the whole figure is 165.12 cm 2.