Circle geometry help (area of sector)?
1. feta = 1/3 radians Area= 2 sq ft r= ?
2. r = 6 meters Area= 8 sq meters feta= ?
3. r = 3 meters feta= 120 degrees Area= ?
Thanks so much!! :)
- LearnerLv 78 years agoFavorite Answer
i) Area of a sector of a circle is given by: A = (1/2)(lr), where l is the arc length and r is the radius of the circle;
(or) A = (1/2)(r²θ), where r is the radius of the circle and θ is the angle of the sector in radians.
ii) In the 1st problem, (1/2)(r²θ) = 2
==> (1/2)r²(1/3) = 2; ==> r² = 12
So r = 2√3 ft
iii) Applying the same as above, in the second, θ = 4/9 radians
iv) In the 3rd, θ = 120*π/180 = 2π/3 [Since 180 deg = π radians]
So A = (1/2)(9)(2π/3) = 3π sq m
- Anonymous8 years ago