Lesson 100 of Similar Triangles 7 4 Applying

Lesson #100 : of Similar Triangles 7 -4 Applying Properties of Similar Triangles Do Now: Answer the following questions about the 2 similar triangles below. D K 21 18 C E J L a) Write a similarity statement for the 2 triangles. CDE JKL b) If the larger triangle has a perimeter of 84, find the perimeter of the smaller. 72 units c) If the smaller triangle has an area of 216, find the area of the larger. 294 units² Holt Geometry

Big Ideas p. 423 -426 7 -4 Applying Properties of Similar Triangles 3: 2 3: 4 Holt Geometry

7 -4 Applying Properties of Similar Triangles Holt Geometry

7 -4 Applying Properties of Similar Triangles Holt Geometry

7 -4 Applying Properties of Similar Triangles *The two triangles are similar. ∆AEF ~ ∆ABC Holt Geometry

Using the Triangle Proportionality Theorem Properties of Similar Triangles 7 -4 Applying Find PN. 2 PN = 15 Holt Geometry PN = 7. 5

7 -4 Applying Properties of Similar Triangles Holt Geometry

of 3 Similar Triangles 7 -4 Applying Properties Example AC = 36 cm, and BC = 27 cm. Verify that . 16 12 Since , by the Converse of the Triangle Proportionality Theorem. Holt Geometry

Applying Properties of Similar Triangles 7 -4 Another Proportionality Theorem Or BD/AB = DC/AC Holt Geometry

Example 4: Using the Triangle Angle Bisector of Similar Triangles 7 -4 Applying Properties Theorem Find PS and SR. 40(x – 2) = 32(x + 5) 40 x – 80 = 32 x + 160 8 x = 240 x = 30 Holt Geometry PS = x – 2 = 30 – 2 = 28 SR = x + 5 = 30 + 5 = 35

of Similar Triangles 7 -4 Applying Properties HW #100: Big Ideas Copy 3 theorems from pages 446 & 449 onto index cards. On pages 450 - 452: Do #’s 1, 2, 4 – 8 (even), 20, 22 -26, 30, 41 -45 Holt Geometry