Question

. The length of the rectangular field is thrice its breath and its area is 1200 m². The length of the field is:
(i) 60 cm (ii) 80 cm (iii) 120 cm
The area of a circle of diameter 14 cm is:
(i) 260 cm2 (ii) 154 cm? (iii) 298 cm2 (iv) 176 cm?
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Answer 1

Answer:

a. ( i ) 60 m

b. ( ii ) 154 cm

Step-by-step explanation:

a ) Given ;

Area of a rectangular field = 1200 sq .m

Let -

Breadth = x

Length = 3x

Area of a rectangular field ( A ) = L× B

A = ( x ) × ( 3x )

A = 3x2

3x2 = 1200

x2 = 1200 / 3

x2 = 400

x = √400

x = 20

Breadth = 20 m

Length = 3x = 3 × 20 = 60 m

b ) Given

Diameter of a circle ( d ) = 14 cm

Radius of Circle ( r ) = d / 2 = 14 / 2 = 7 cm

Area of a circle ( A ) = πr2

A = 22 / 7 × 7 × 7

A = 22 × 7

A = 154 sq . cm

Hence ,

Area of a circle = 154 cm2