In a circle, a 315 degree sector has area 686pie^2. What is the radius of the circle

Answer 1

I assume you meant pi, not pie.......

first, write an expression for the area of the full circle: A = ( 360 / 315 ) *686*pi^{2 =} 784*pi²

A = pi * r², so we can write:

784*pi^{2 =} pi * r²

And: r^{2 =} 784*pi

solve this to get r