# NCERT Class 9 Solutions: Heron՚s Formula (Chapter 12) Exercise 12.2 Part 2 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Q-3 Radha made a picture of an airplane with colored paper as shown in figure. Find the total area of the paper used.

Solution:

We can divide the airplane into the separate quadrilaterals and triangles. let՚s find each of their areas

For triangle (i)

This triangle is an isosceles triangle, therefore its perimeter and semi-perimeter

By using heroes formula, area of the triangle

• (approx.)

Area of Rectangle

This quadrilateral is a trapezium. To find the area we need to first find its height. =

• Perpendicular height of parallelogram
• Area = area of parallelogram + area of equilateral triangle

For triangle (IV) = triangle (v)

We know

• (2 triangle)

Therefore, total area of the paper used

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