AOB is a sector of a circle such that angle AOB=60degrees?

Question

and OB is r units long. The area, in square units, of AOB is?

Answer 1

As 60° is 1/6 of a full circle, the area will be 1/6 of the area of a full circle:
A = (1/6)πr² = πr²/6

Another way of doing the same thing is to convert the angle to radians. θ = 60° = π/3 rad, so plug it into the formula:
A = θr²/2
(This formula only works if the angle θ is expressed in radians.)

For your example, that gives the same answer of course:
A = (π/3)r²/2 = πr²/6

Answer 2

If OB is r units long, then the radius of the entire circle is r. If the "sector" was 360 degrees then we'd have a full circle. So a sector of 60 degrees is 60/360 = 1/6 of the circle. So just find the area of the full circle (you know the raidus is "r", so this should be easy) and take 1/6 of it.

Answer 3

easy.

AOB is a 6th of the circle (60/360)

OB, or the radius= r units

Area of circle= pi r2

Area of AOB= (Pi R2)/6

I don't think that it can be cancelled down much more.

Answer 4

pi*r^2*60/360

=pi*r/3

Answer 5

(3.14 r^2)(60/360)=(3.14 r^2 )/6=(3.14/ 6)r^2