Question

3. Radha made a picture of an aeroplane with coloured paper as shown in Fig 12.15. Find
the total area of the paper used.
5cm
6cm
IV
V
1.5cm
6.5cm
cm
Icm
Icm
2cm​

Answer 1

Answer:

For triangle I

This triangle is an

isosceles triangle.

Perimeter = 2s =

(5 + 5 + 1) cm = 11cm

Area of the triangle

For quadrilateral II

This quadrilateral is a

rectangle.

Area = l × b

= (6.5 × 1) cm2 = 6.5 cm2

For quadrilateral

III

This quadrilateral is a

trapezium.

Perpendicular height of

parallelogram

Area = Area of

parallelogram + Area of equilateral triangle

=

0.866 + 0.433 = 1.299 cm2

Area of triangle (IV) =

Area of triangle in (V)

Total area of the paper

used = 2.488 + 6.5 + 1.299 + 4.5 × 2

=

19.287 cm2