Q11 of 50 Page 13

Find the area os the shaded region in Fig. 12.12.

In side (AB)2 = (AD)2 + (BD)2


(AB)2 = (12)2 + (16)2


AB =


AB = = 20 cm


In


Let a, b and c are the sides of triangle and s is the semi-perimeter, then its area is given by:


A = where [Heron’s Formula]



= = 24


A1 =


A1 = = cm2


In


Let a, b and c are the sides of triangle and s is the semi-perimeter, then its area is given by:


A2 = where



= = 60


A2 =


A2 = = cm2


Area of shaded region is A2-A1 = 480 – 96 = 384 cm2


More from this chapter

All 50 →
9

The lengths of the sides of a triangle are in the ratio 3 : 4 : 5 and its perimeter is 144 cm. Find the area of the triangle and the height corresponding to the longest side.

 10

The perimeter of an isosceles triangle is 42 cm and its base is (3/2) times each of the equal sides. Find the length of each side of the triangle, area of the triangle and the height of the triangle.

 1

Find the area of a quadrilateral ABCD is which AB = 3 cm, BC = 4 cm, CD = 4 cm, DA = 5 cm and AC = 5 cm.

 2

The sides of a quadrangular field, taken in order are 26 m, 27 m, 7 m, are 24 m respectively. The angle contained by the last two sides is a right angle. Find its area.