1. * Solving a Right
Triangle When
Given an Angle and
a Side and Molly
Group 1
Sam, John, Ashleigh,

2. B
c
12.7 in a
A C
b
This is the given problem. Solve for angle B.
Also solve for side A and B.

3. B
c
12.7 in a A=7.19 inches
A C
b
Solving Side A:
Sin A = a/c
Sin 34˚30’ = a/12.7
a = 12.7 sin 34˚30’ : Multiply by 12.7 and rewrite
a = 12.7 sin 34.5˚ : Convert to decimal degrees
a = 12.7 (0.56640624)
a = 7.19 inches

4. B
c
12.7 in a
A C
b
B = 10.5 inches
Solving Side B:
Cos A = b/c
Cos 34˚30’ = b/12.7
b = 12.7 cos 34˚30’ : Multiply by 12.7 and rewrite
b= 10.5 inches

5. B
c
12.7 in a
A C
b
Solving Angle B:
Angle A is 34.5˚
You take 180-90-34.5
B= 55.5˚

6. If you have a different angle and side, you use the same method but must determine
whether you need to use SIN, COS, or TAN.