Geometry Lesson 7 5 Parts of Similar Triangles

Geometry Lesson 7 – 5 Parts of Similar Triangles Objective: Recognize and use proportional relationships of corresponding angle bisectors, altitudes, and medians of similar triangles. Use the Triangle Bisector Theorem.

Theorem Special Segments of Similar Triangles Theorem 7. 8 l If two triangles are similar, the lengths of corresponding altitudes are proportional to the lengths of corresponding sides.

Theorem 7. 9 l If two triangles are similar, the lengths of corresponding angle bisectors are proportional to the lengths of corresponding sides.

Theorem 7. 10 l If two triangles are similar, the lengths of corresponding medians are proportional to the lengths of corresponding sides.

In the figure ABC ~ FDG. Find the value of x. 12 x = 120 x = 10

Find the value of x. 240 = 20 x 12 = x 40. 5 = 9 x 4. 5 = 9

Real World Liliana holds her arm straight out front of her with her elbow straight and her thumb pointing up. Closing one eye, she aligns one edge of her thumb with a car she is sighting. Next she switches eyes without moving her head or arm. The car appears to jump 4 car widths. If Liliana’s arm is about 10 times longer than the distance between her eyes, and the car is about 5. 5 feet wide, estimate the distance from Liliana’s thumb to the car. 220 = x The estimated distance to the car is 220 feet.

Homework Pg. 498 1 – 5 all, 6 – 22 E, 32, 36 – 48 E