Book: RD Sharma - Mathematics
Chapter: 20. Mensuration-I (Area of a Trapezium and a Polygon)
Subject: Maths - Class 8th
Q. No. 2 of Exercise 20.3
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Find the area enclosed by each of the following figures [fig. 20.49 (i)-(ii)] as the sum of the areas of a rectangle and a trapezium.
Figure (i)
Area of given figure = Area of trapezium + area of rectangle
Area of given figure = 
Area of given figure = 
Area of given figure = 
Therefore area of given figure is 424 cm2
Figure (ii)
Area of given figure = Area of trapezium + area of rectangle
Area of given figure = 
Area of given figure = 
Area of given figure = 
Therefore area of given figure is 384 cm2
Figure (iii)
Using pythagorous theorem in the right angled triangle
52 = 42 + x2
x2 = 25 – 16
x2 = 9
x = 3 cm
Area of given figure = Area of trapezium + area of rectangle
Area of given figure = 
Area of given figure = 
Area of given figure = 
Therefore area of given figure is 54 cm2
