Question

Which one of the following is the area of a sector of a circle of radius 10 cm formed by an arc length of 15 cm?

Answer 1

Answer:

Given.,

Radius =10cm

Arc length =15cm

therefore Area of sector=1÷2×radius ×arc length

=1÷2×10×15

=5×15

=75 Sq cm

Answer 2

Answer:

75 cm²

Step-by-step explanation:

It is given that radius of the circle is 10 cm and arc length of a sector is 15 cm.

$r=10$

$l=15$

Formula for arc length:

$l=r\theta$           .... (1)

Area of sector:

$A=\frac{1}{2}r^2\theta$         .... (2)

where r is radius and θ is central angle in radian.

Using (1) and (2) we get

Area of sector is

$A=\frac{1}{2}rl$

Substitute r=10 and l=15 in the above formula.

$A=\frac{1}{2}\times 10\times 15$

$A=75$

Therefore the area of the sector is 75 cm².