Trig: !!!!!!!!!!!!!!

Question

1) Find the radius of a circle if the measure of the central angle, 2pi/3 , intercepts an arc with a length of 6pi centimeters.?

A)18 cm 
B)12 cm 
C)9 cm 
D)5 cm 

2.) Find the radius of a circle if the measure of the central angle, 2pi/3 , intercepts an arc with a length of 4pi centimeters. Use 

A)32 cm 
B)16 cm 
C)9cm 
D)6cm 

Find the measure of the central angle with a radius of 13 inches and the area of a sector measuring 84.5pi square inches. 
Choices: 
45 degrees 
90 degrees 
120 degrees 
180 degrees 

Find the measure of the central angle with a radius of 18 inches and the area of a sector measuring 40.5pi square inches. 

A)45 degrees 
B)90 degrees 
C)120 degrees 
D)180 degrees

 

 

Answer 1

1) L = 6pi, central angle 2pi/3

Calculate the radius by using formula arc legth

Option C is correct answer.

2) L = 4pi, central angle 2pi/3

Calculate the radius by using formula arc legth

Option D is correct answer.

3) A = 84.5 pi, r = 13

Substitute the values r² = 169, A = 84.5 in the formula.

Option 4 is correct choice.

4) A = 40.5 pi, r = 18

r² = 18*18 = 324

Substitute the values in the formula.

Option A is correct choice.