# NCERT Class 9 Solutions: Heron's Formula (Chapter 12) Exercise 12.2 Part 2

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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.)

**For quadrilateral (ii)**

Area of Rectangle

**For quadrilateral (iii)**

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