1. R EVIEW LESSONS 4.1 TO 4.4 Honors Geometry

2. C LASSIFYING T RIANGLES Every triangle can be classified 2 ways: --by the side lengths --by the angle measures

3. C LASSIFYING T RIANGLES Classification by sides: Equilateral, Isosceles, Scalene Classification by angles: Acute, Equiangular, Right, Obtuse Chart on classification -- textbook page 194

4. P OSSIBLE NAME COMBINATIONS Acute ScaleneRight Obtuse Acute IsoscelesRight Obtuse EquilateralEquiangular Acute a) Draw each of the seven triangles listed here. b) List the names of at least 2 other triangles that would be impossible to draw. Chart on classification -- textbook page 194 #1

5. T RIANGLE S UM T HEOREM The three angles of a triangle add up to 180° These expressions represent the angle measures of a triangle. Find the measure of each angle, then classify the triangle by its angles. m  K = 10(x + 1)° m  L = (9x – 3)° m  M = (7x – 9)° #2

6. E XTERIOR A NGLE T HEOREM The measure of an exterior angle of a triangle is equal to the sum of the measures of the two nonadjacent interior angles. #3 1 2 3 m  1 + m  2 = m  3 Find the measure of the exterior angle shown below. 110° (4x – 7)° x°

7. C ONGRUENT T RIANGLES Congruent triangles are the same size and shape Angles that are the same size are called corresponding angles. Sides that are the same length are called corresponding sides. When writing a congruence statement, the order of the letters matters. For example, the statement ∆XYZ  ∆STR, tells us all of the following:  X  S,  Y  T,  Z  R and Segments XY and ST are congruent, as are segments YZ and TR and segments XZ and SR

8. U SING PROPERTIES OF CONGRUENT FIGURES In the diagram ABCD  KJHL. Find the value of x and y. #4 AB C D K J H L 91° 86° 113° 9 cm 6 cm (4x – 3) (5y – 12)°

9. U SING PROPERTIES OF CONGRUENT FIGURES Find the value of x. Write a congruence statement for the two triangles. #5 A B C D E F 22° 87° (4x + 15)°

10. C ONGRUENCE S HORTCUTS We have learned 4 shortcuts for proving triangles are congruent: SSS, SAS, ASA, AAS. For each of the following, tell if there is enough information to prove the triangles are congruent. If so, tell which congruence shortcut you would use. AB #6

11. A NSWERS 2. x = 7, m  K = 80°, m  L = 60°, m  M = 40°, acute 3. x = 39, 149° 4. x = 3, y = 25 5. x = 14, ∆ABC  ∆DEF 6. A yes, SAS B yes, AAS