Classify the triangle. A. scalene B. isosceles C. equilateral 5-Minute Check 1

Find x if mA = 10x + 15, mB = 8x – 18, and mC = 12x + 3. 5-Minute Check 2

Name the corresponding congruent sides if ΔRST  ΔUVW. A. R  V, S  W, T  U B. R  W, S  U, T  V C. R  U, S  V, T  W D. R  U, S  W, T  V 5-Minute Check 3

Name the corresponding congruent sides if ΔLMN  ΔOPQ. B. C. D. , 5-Minute Check 4

5-Minute Check 5-Minute Check 6 Find y if ΔDEF is an equilateral triangle and mF = 8y + 4. A. 22 B. 10.75 C. 7 D. 4.5 5-Minute Check 5-Minute Check 6

You used segment and angle bisectors. Identify and use perpendicular bisectors in triangles. Identify and use angle bisectors in triangles. Then/Now

Concept

Use the Perpendicular Bisector Theorems A. Find BC. Example 1

Use the Perpendicular Bisector Theorems B. Find XY. Example 1

Use the Perpendicular Bisector Theorems C. Find PQ. Example 1

A. Find NO. A. 4.6 B. 9.2 C. 18.4 D. 36.8 Example 1

B. Find TU. A. 2 B. 4 C. 8 D. 16 Example 1

C. Find EH. A. 8 B. 12 C. 16 D. 20 Example 1

Concept

Use the Angle Bisector Theorems A. Find DB. Example 3

Use the Angle Bisector Theorems B. Find mWYZ. Example 3

Use the Angle Bisector Theorems C. Find QS. Example 3

A. Find the measure of SR. A. 22 B. 5.5 C. 11 D. 2.25 Example 3

B. Find the measure of UV. A. 7 B. 14 C. 19 D. 25 Example 3

C. Find the measure of HFI. B. 30 C. 15 D. 30 Example 3

Concept

Concept

A. Find ST if S is the incenter of ΔMNP. Use the Incenter Theorem A. Find ST if S is the incenter of ΔMNP. Example 4

B. Find mSPU if S is the incenter of ΔMNP. Use the Incenter Theorem B. Find mSPU if S is the incenter of ΔMNP. Example 4

A. Find the measure of GF if D is the incenter of ΔACF. B. 144 C. 8 D. 65 Example 4

Example 4End of the Lesson B. Find the measure of BCD if D is the incenter of ΔACF. A. 58° B. 116° C. 52° D. 26° Example 4End of the Lesson