A sector of a circle has perimeter 7cm and area 3cm^2. Find all possible radii.

Question

anonymous · Answer

idk

anonymous · Answer

best answer

superdavesuper · Answer

lets assume the radius is r and the enclosed angle of the sector is theta, we can set up the eqns for perimeter n area....

superdavesuper · Answer

|dw:1389858276135:dw|

ranga · Answer

Length of the arc = r * theta      (theta is in radians)
Perimeter of the sector = 2r + r * theta = 7   ---- (1)
Area of the sector = 1/2 * r^2 * theta = 3   ----- (2)

Eliminate theta from (1) and (2) and solve for r.

anonymous · Answer

I attempted to do it but my answers are still incorrect. I keep ending up with 1.11 instead of 1.5.

superdavesuper · Answer

Nope 1.5 is one of the right answer; plz try to solve the two equations again as ranga has set up above.

anonymous · Answer

The answer is in the attachment.

anonymous · Answer

Thank you for including how to do it step by step! I was lost half way through the equation and did not know where my mistake was.