Okay, I have a question on an exam paper that I just can't seem to do.
Well okay. It's a circle. It's been cut. So we have a triangle and a sector.
The radius is 4cm. The sector area is Acm^2 and the perimeter is Xcm and X = 3A.
Now. I have to show with that information that the angle is 0.4radians.
I can't figure it out.
I need to figure out the perimeter. Then I can just sub it into 1/2*R^2*the angle in radians and then BAM I should have showed it.
Silly me. Suddenly all makes sense.
Well you see. I read the question a bit queerly. You see, I thought X was the perimeter of the triangle, but upon reading again I found out X was actually the perimeter of the sector.
So X = rθ +2r = 4θ + 8
A = 0.5rēθ = 8θ
So X = 24θ = 4θ + 8
From then I got that θ = 0.4
I always make these damned silly mistakes.