Question

Please write the correct way also?​

Answer 1

Step-by-step explanation:

Let AOB be the sector with O as center...

Given radius=r= 4.2 cm

Perimeter of sector=12.8

So, OA+AB+OB=12.8

==> 4.2+4.2+AB=12.8

==> AB= 12.8-4.2-4.2

==> AB=4.4 cm

.°. Area of sector

$\frac{1}{2} \times r \times l$

$= \frac{1}{2} \times 4.2 \times 4.4$

$= 9.24cm {}^{2}$

Answer 2

Answer:

80.64 cm^2

Step-by-step explanation:

let the angle be x

We know that,

perimeter of sector = angle ÷360°× 2πr

12.8=x÷360°×2πr

x=12.8×360÷2π×4.2

x=64×30÷11. ( we don't solve it fully as it will be complex)

Now , area of sector = angle÷360×πr^2

=( 64×30÷11×360 ) 22÷7 ×4.2×4.2

= 80.64