Use the Triangle Angle-Sum Theorem

SOFTBALL The diagram shows the path of the softball in a drill developed by four players. Find the measure of each numbered angle.

Understand Examine the information in the diagram. You know the measures of two angles of one triangle and only one measure of another. You also know that 1 and 2 are vertical angles.

Use the Triangle Angle-Sum Theorem

Answer: Therefore, m1 = 63, m2 = 63, and m3 = 38.

Check The sums of the measures of the angles in each triangle should be 180.

m1 + 43 + 74 = 63 + 43 + 74 or 180m2 + m3 + 79 = 63 + 38 + 79 or 180

A. A

B. B

C. C

D. D

A. 95

B. 75

C. 57

D. 85

Find the measure of 3.

Use the Exterior Angle Theorem

GARDENING Find the measure of FLW in the fenced flower garden shown.

Answer: So, mFLW = 2(80) – 48 or 112.

A. A

B. B

C. C

D. D

A. 30

B. 40

C. 50

D. 130

The piece of quilt fabric is in the shape of a right triangle. Find the measure of ACD.

A corollary is a theorem with a proof that follows as a direct result of another theorem. As with a theorem, a corollary can be used as a reason in a proof. These corollaries follow directly from the sum theorem

Find Angle Measures in Right Triangles

Find the measure of each numbered angle.

m1 = 104, m2 = 76, m 3 = 42, m4 = 48, m5 = 49

A. A

B. B

C. C

D. D

A. 50

B. 45

C. 85

D. 130

Find m3.