Question

If the area of circular shaped dart board is 1386 sq.cm. Find its radius and diameter.​

Answer 1

Answer:

Correct option is A)

Area of a circle of radius r =πr

2

=1386cm

2

7

22

×r

2

=1386cm

2

r

2

=441cm

2

r=21cm

Circumference of a circle of radius r =2πr

Circumference of circle of radius 21cm=2×

7

22

×21=132cm

Answer 2

Answer:

If the area of circular-shaped dartboard is 1386 sq.cm then its radius is 21cm and diameter is 42 cm.​

Step-by-step explanation:

Given:

The area of the circular-shaped dartboard is 1386 sq.cm.

Find: Radius and diameter

Formula: Area of circle = $\pi r^{2}$

The area of the circular-shaped dartboard = 1386 sq.cm.

$\pi r^{2} =1386\\\frac{22}{7} r^{2} =1386\\r^{2} =1386 \times \frac{7}{22} \\r^{2} =63 \times 7\\r^{2} = 441\\r = 21 cm$

So, the radius of circular-shaped dartboard is 21 cm

And the diameter of circular-shaped dartboard is (21 × 2 =) 42 cm