The circumference of a circle is given by 2πr and the area is given by πr2 , where r represents the radius of the circle. Which of these represent an irrational number? Select ALL that apply.

Question

The circumference of a circle is given by 2πr and the area is given by πr2 , where r represents the radius of the circle. Which of these represent an irrational number? Select ALL that apply.

A. the circumference of a circle with a radius of 2π units

B. the area of a circle with a radius of 2π units

C. the area of a circle with a radius of 2π units

D. the radius of a circle with a circumference of 2 units

E. the radius of a circle with an area of 2 units2

F. the circumference of a circle with a radius of 2π units

Answer 1

A. C=2pir = 2pi(2pi) = 4pi^2 is irrational

B A=pir^2 = pi(2pi)^2 = 4pi^3 is irrational

C. same as B, irrational

D. C=2pir = 2, radius = 1/pi which is irrational

E. A=pir^2 = 2, r^2 = 2/pi, r= sqr(2pi) which is irrational

F C=2pir = 2pi(2pi) = 4pi^2, same as A which is irrational

They're all irrational numbers involved pi which is irrational.