A sector with a radius 12 cm has an area of 60 pi cm2. What is the central angle measure of the sector in degrees?

The central angle measure of the sector is 150º.

Step-by-step explanation:

A sector of a circle is the portion of a circle enclosed by two radii and an arc.

When you know the central angle the area of a sector is given by

where

r is the radius of the circle of which the sector is part.

C is the central angle in degrees.

We know that the area of the sector is and the radius is 12 cm. Applying the above formula and solving for the central angle we get that

there are lots of ways.   pick's theorem tells us if the vertices are lattice points the area a is

a = b/2 + i - 1

where b is the number of boundary lattice points and i is the number of interior lattice points.

in the figure i count b=16, i=50 so

a = 8 + 50 - 1 = 57

let's try the shoelace formula.   the area is half the sum of the cross products of the sides.  

a(-2,6)   -2(2)-6(-5) = 26

b(-5,2)   -5(-3) - 2(-2) = 19

c(-2,-3) -2(-3) - (-3)(4) = 18

d(4,-3)   4(3) - (-3)(5) = 27

e(5,3)   5(3) - 3(1) = 12

f(1,3)     1(6) - 3(-2) = 12

a(-2,6)

each of the cross products is twice the area of the triangle with the associated side and one vertex the origin. so the area of abo=26/2=13.

area = (1/2) (26 + 19 +   18 + 27 + 12 + 12) = 57

that checks!

care to share were the trapezoid shown is ?