Question

What is the area of the shaded portion in the given figures?

Answer 1

Answer:a) 140 cm^

b)150m^2

Explanation:

a)first find the area of big rectangle i.e rectangle

area of rectangle 1 = length ×breadth

area of rectangle = 10×20=200cm^2

now find area of small rectangle i e rectangle

area of rectangle 2 = 12×5=60cm^2

now subtract area of rectangle 2 from area of rectangle

area of shaded portion =200-60= 140cm^2

b)find area of big triangle i.e triangle 1....

area of triangle 1 = 1/2 × base × height...

area of triangle 1 =1/2×20×20 = 200m^2

area of triangle 2 =1/2×10×5 =25m^2

area of triangle 3=1/2×10×5= 25m^2

area of shaded portion = area of triangle 1 - area of triangle 2 - area of triangle

area of shaded portion =200-25-25 =150m^2

Answer 2

a) 40cm²

b) 150cm²

Explanation:

a)

The area of the shaded region is equal to the area of the larger rectangle, minus the area of the smaller rectangle.

Knowing the formula for the area of a rectangle is bh (where b is base and h is height), we can find

Large rectangle area: bh = (20)(10) = 200cm²

Smaller rectangle area: bh = (12)(10) = 120cm²

The area of the shaded region is therefore 200-120cm²=80cm²

b)

The area of the shaded region is equal to the area of the larger triangle, minus the area of the smaller triangle.

Knowing the formula for the area of a triangle is 0.5bh (where b is base and h is perpendicular height), we can find

Large triangle area: 0.5bh = 0.5(20)(20) = 10(20) = 200cm²

Smaller triangle area: 0.5bh = 0.5(20)(5) = 10(5) = 50cm²

The area of the shaded region is therefore 200-50cm²=150cm²