Help please i’m confused

7/10 pi (radians)

Step-by-step explanation:

The formula for sector area is (angle * r^2)/2

140pi = angle*r^2/2

multiply both sides by 2

280pi = angle * r^2

r = 20 cm (substitute)

280pi = angle * (20)^2

280pi = angle * 400

Divide both sides by 400

7/10 pi = angle

the simplified form is

step-by-step explanation:

we want to simplify the expression,

let us change the middle bar to a normal division sign to obtain,

we multiply the first fraction by the reciprocal of the second fraction to obtain,

we factor to obtain,

we cancel the common factors to get,

we simplify to get,

the correct answer is b