Trigonometric Functions
posted by Julia .
A 2(pi) cm wire is stretched along a circle of radius 4cm. The degree measure of the central angle subtended by this wire arc is what?

circumference = 2 pi r = 8 pi
fraction of circumference = 2 pi/8 pi = 1/4
1/4 * 360 = 90 degrees 
A chord of a circle is 15 cm long and subtends at an angle of 110° at the center of the circle. Find the radius of the circle correct to 2 decimal point.