Homework, red pen, pencil, highlighter, ruler, GP NB U3D8 Homework, red pen, pencil, highlighter, ruler, GP NB Have Out: Bellwork: Graph the inequality: +1 Dividing line: +1 y x 1 2 3 4 5 -1 -2 -3 -4 -5 Test point (0, 0) +2 False y-int: (0,1) +1 +1 +1 +1 for labeling axes & scale

Send one member of your team to pick up: PS-92 Angles and Triangles About a half page down, draw a horizontal line using a ruler. Place a point in the middle of your line and label it A. A Send one member of your team to pick up: Triangle worksheet (ONE per group) Scissors (TWO per group)

Number the corners of your triangle with 1, 2, and 3. PS-92 Angles and Triangles Your team has been given 4 different triangles. Notice that every triangle has a different shape. 1 3 2 Each team member will have their own triangle. Highlight each of the edges of your triangle. Number the corners of your triangle with 1, 2, and 3.

PS-92 1 3 2 3.Separate off each corner of the triangle in LARGE PIECES by tearing along a jagged edge.

PS-92 1 3 2 3.Separate off each corner of the triangle in LARGE PIECES by tearing along a jagged edge. 4.Place the 3 resulting angles so that they are adjacent angles on the UPPER side of the line in your notebook with all 3 vertices at the labeled point A. Tape the corners together at point A. Be sure that the angles do not overlap. A

Write a conjecture about the sum of the 3 angles of any triangle. PS-92 5.Compare your results with your team. What do you notice? Write a conjecture about the sum of the 3 angles of any triangle. The sum of the 3 angles of any triangle is 180°. 2 1 3 A

>> If m1=m4 and m3=m5 and then by substitution PS-93 Justify your answers for the following. A) They are adjacent angles that form a straight angle. >> 1 2 3 B 4 A 5 C B) || Alternate interior s are equal. C) || Alternate interior s are equal. D) How can you put the equations from parts (A), (B), and (C) together to form an equation that represents the sum of the interior angles of a triangle? If m1=m4 and m3=m5 and then by substitution m4 + m2 + m5 = 180.

The sum of the measures of the interior angles of a triangle is 180°. PS-93 Add to your notes: This process proves the conjecture, and a proven conjecture is known as a theorem. Triangle Interior Angle Sum Theorem ( sum thm) The sum of the measures of the interior angles of a triangle is 180°. The TRIANGLE INTERIOR ANGLE SUM THEOREM is a theorem because doing parts (A) – (D) produced a sequence of true, connected facts that verify the final statement.

PS-96 Find the measures of the missing angles by using the theorem about the sum of the measures of the angles of a triangle. x A) B) C) 80° 90° 60° x x x x x D) E) F) 70° 62° 20° 50° x x 120° x

90° + 60° + x = 180° 80° + x + x = 180° x + x + x = 180° ( sum thm) PS-96 Find the measures of the missing angles by using the theorem about the sum of the measures of the angles of a triangle. x A) B) C) 80° x 90° 60° x 90° + 60° + x = 180° 80° + x + x = 180° x + x + x = 180° ( sum thm) ( sum thm) ( sum thm) 150° + x = 180° 80° + 2x = 180° 3x = 180° -150° -150° -80° -80° 3 3 x = 30° 2x = 100° x = 60° 2 2 x = 50°

62° + 50° + x = 180° y + 120° = 180° 20° + 90° + x = 180° -120° -120° PS-96 Find the measures of the missing angles by using the theorem about the sum of the measures of the angles of a triangle. D) E) F) 120° 70° x 50° 62° x 20° x y (Linear pair) 62° + 50° + x = 180° y + 120° = 180° 20° + 90° + x = 180° -120° -120° ( sum thm) ( sum thm) y = 60° 112° + x = 180° 110° + x = 180° -112° -112° 70° + y + x = 180° -110° -110° ( sum thm) x = 68° x = 70° 70° + 60° + x = 180° 130° + x = 180° -130° -130° x = 50°

Finish the rest of the assignment... Work on PS 115...then Finish the rest of the assignment... PS 97 - 102. Quiz Thursday!