Download presentation
1
Geometry 5.2 Inside Out
2
5.2 Triangle Sum, Exterior Angle, and Exterior Angle Inequality Theorems
Objectives Prove the triangle sum theorem Explore the relationship between the interior angle measures and the side lengths of a triangle Identify the remote interior angles of a triangle Identify the exterior angle of a triangle Explore the relationship between the exterior angle measures and two remote interior angles Prove the Exterior Angle Theorem Prove the Exterior Angle Inequality Theorem
3
Yes Can subtract from 180 to find the interior angles (linear pairs) Then all angles inside add to 180 Subtract from 180 to solve for x (linear pair)
4
π₯=180β128 π₯= 52 π Linear Pair Postulate 52+75+π¦=180 π¦+127=180 π¦= 53 π
5
Problem 1 Triangle Interior Angle Sums
#1 Triangle Sum Theorem Draw a triangle on a sheet of paper Tear off the angles Place them next to each other What do you notice about the sum of these angles? βThe sum of the measures of the interior angles of a triangle is 180 π .β
6
ππππππππ π΄π΅πΆ π€ππ‘β π΄π΅ β₯ πΆπ·
πβ 4+πβ 3+πβ 5= 180 π β 1β
β 4, β 2β
β 5 πβ 1=πβ 4, πβ 2=πβ 5 πβ 1+πβ 3+πβ 2= 180 π πβ 1+πβ 2+πβ 3= 180 π πΊππ£ππ π΄ππππ π΄ππππ‘πππ πππ π‘π’πππ‘π π΄ππ‘πππππ‘π πΌππ‘πππππ π΄ππππ πβπ π·ππππππ‘πππ ππ πΆπππππ’πππ‘ π΄πππππ ππ’ππ π‘ππ‘π’π‘πππ πππππππ‘π¦ π΄π π πππππ‘ππ£π πππππππ‘π¦
7
Problem 2: Analyzing Triangles
Collaborate 1, 2, or 3 (5 Minutes) Use Ruler and Protractor Each member of the group will do only one drawing Collaborate 4-6 (3 Minutes)
8
Problem 2: Analyzing Triangles
Discuss #7 Together 47 π 98 π 95 π 112 π
9
Formative Assessment Skills Practice 5.2 Pg (1-12)
10
5.2 Triangle Sum, Exterior Angle, and Exterior Angle Inequality Theorems
Objectives Prove the triangle sum theorem Explore the relationship between the interior angle measures and the side lengths of a triangle Identify the remote interior angles of a triangle Identify the exterior angle of a triangle Explore the relationship between the exterior angle measures and two remote interior angles Prove the Exterior Angle Theorem Prove the Exterior Angle Inequality Theorem
11
Problem 3: Exterior Angles
Collaborate 1-8 (4 Minutes) Remote Interior Angles of a Triangle The two angles that are non-adjacent to the specified exterior angle
12
Problem 3: Exterior Angles
Collaborate 9-12 (4 Minutes) Exterior Angle Theorem The measure of the exterior angle of a triangle is equal to the sum of the measures of the two remote interior angles of the triangle. πβ 4=πβ 1+πβ 2
13
Sketchpad Example 5.2 Day 2 Exterior Angles
14
Problem 3: Exterior Angles
Discuss #14 Together
15
Problem 3: Exterior Angles
Discuss #14 Together
16
Problem 3: Exterior Angles
Exterior Angle Inequality Theorem The measure of an exterior angle of a triangle is greater than the measure of either of the remote interior angles of a triangle πβ 4>πβ 1 πππ πβ 4>πβ 2
17
Talk the Talk Pg. 403 Collaborate 2 Minutes
Shortest to Longest b, a, c, e, d c a d ππ πππ π‘βπ π‘πππππππ ππ π‘βπ πππβπ‘, π‘βπ π πππ πππππ ππ‘π π‘βπ 32 π πππππ ππ π‘βπ π βπππ‘ππ π‘ π πππ, πππππ ππ‘π π‘βπ 58 π πππππ ππ πππ₯π‘ πππ πππππ ππ‘π π‘βπ 90 π ππ π‘βπ ππππππ π‘ π πππ πΉπ’ππ‘βππππππ, π€βππ π’π πππ π‘βπ π‘πππππππ ππ π‘βπ ππππ‘, π‘βπ π πππ πππππ ππ‘π π‘βπ 32 π πππππ ππ π‘βπ π βπππ‘ππ π‘ π πππ π‘βπ π πππ πππππ ππ‘π π‘βπ 43 π πππππ ππ πππ₯π‘ πππ π‘βπ π πππ πππππ ππ‘π π‘βπ 105 π πππππ ππ π‘βπ ππππππ π‘ π πππ Lemon and Grape Islands are farthest apart
18
Formative Assessment Skills Practice 5.2 Pg. 483 Vocabulary (1-4)
Turn in all of 5.2 on the round table when finished. Both assignments are due today.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.