College Math Survey
3.1- 3.2 Review Worksheet
Mathematician __________________________
10.13.15
Section 3.1:
Convert from degrees to radians.
Convert from radians to degrees.
Understand the difference between an exact answer and an approximation.
Section 3.2:
Find the length of an arc, or the radius or the central angle.
Find the area of a sector, or the radius or the central angle.
s = rθ
1
A = r 2θ
2
Examples – CONVERTING UNITS
A)
Convert each degree measure to radians. Give an exact answer – no decimals!
270o
B)
Convert each radian measure to degrees. Give an exact answer – no decimals!
5π
6
C)
Convert each radian measure to degrees. Give an approximate answer – use decimals!
0.456 radians
Practice – CONVERTING UNITS
1)
Convert each radian measure to degrees. Give an exact answer – no decimals!
A)
2)
B)
π
6
Convert each degree measure to radians. Give an exact answer – no decimals!
A)
3)
9π
4
150o
B)
270o
Convert each radian measure to degrees. Give an approximate answer – use decimals!
A)
2.59 radians
B) -0.75 radians
Examples – ARC LENGTH
Missing s.
Missing r.
Missing θ .
The angle is not in radians!!!
Practice – ARC LENGTH s = r θ
1)
2)
Find the radius of each circle given the central angle θ =
π
4
and arc length s = 5π
Find the measure of the central angle given the length of the arc and the radius.
3)
Find the length of the arc s intercepted by a central angle of θ =
4π
in a circle with a
3
radius r = 15.2cm .
Examples – AREA OF A SECTOR
Missing A.
Problems – AREA OF A SECTOR A =
1)
Missing θ . THE BEAST!!!
1 2
r θ
2
Find the area of the sector having radius r = 29.2m and central angle θ =
5π
.
6
2)
Find the measure of the central angle of a circle with a radius r = 8 and an area of
the sector of A = 12π .
3)
Find the area of the sector having radius r and length of arc s. THE BEAST!!