Study Guide and Intervention (continued) - MathnMind

11-7
Solve Triangles Finding the measures of all angles and sides in a right triangle is
called solving the triangle. You can use trigonometric ratios or the Pythagorean Theorem
to find missing side measures.
Example
Find all of the missing measures in ABC.
Step 1 Since the sum of the measures of the angles of a triangle is 180°,
mB 180° 90° 48° 42°.
Step 2 Find the value of x.
x
sin 48°
10
Definition of sine
x
0.7431
10
Evaluate sin 48°.
7.4 x Multiply by 10.
Step 3 Find the value of y.
y
cos 48°
10
Definition of cosine
y
0.6691
10
Evaluate cos 48°.
6.7 y Multiply by 10.
So the missing measures are 42°, 7.4 in., and 6.7 in.
Exercises
Solve each triangle. State the side lengths to the nearest tenth and the angle
measures to the nearest degree.
1. B
2. B
3.
A
4. B
5. C
6.
24
C
NAME ______________________________________________ DATE ____________ PERIOD _____
20
Study Guide and Intervention (continued)
Trigonometric Ratios
33
30
C
A
C
B
45
10
15
A
© Glencoe/McGraw-Hill 680 Glencoe Algebra 1
56
A
A
B
8
C
50
53
A
y
C
B
C
15
48
10 in.
x
A
B