Lesson 5-3 Inequalities in one Triangle. Vocabulary Theorem 5.8: Exterior Angle Inequality The...

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Lesson 5-3 Inequalities in one Triangle

Transcript of Lesson 5-3 Inequalities in one Triangle. Vocabulary Theorem 5.8: Exterior Angle Inequality The...

Lesson 5-3 Inequalities in one

Triangle

VocabularyTheorem 5.8: Exterior Angle InequalityThe measure of an exterior angle of a

triangle is greater than the measure of either of its corresponding remote interior angles.

Example 1

A.B.C.D.

Example 1

A.B.C.D.

VocabularyTheorem 5.9: Angle-Side Relationship #1If one side of a triangle is longer than

another side, then the angle opposite the longer side has a greater measure than the side opposite the shorter side.

VocabularyTheorem 5.10: Angle-Side Relationship #2If one angle of a triangle has greater

measure than another angle, then the side opposite the greater angle is longer than the side opposite the lesser angle.

Example 2Order Triangle Angle Measures

List the angles of ΔABC in order from smallest to largest.

Answer: C, A, B

Example 2

A. X, T, V

B. X, V, T

C. V, T, X

D. T, V, X

List the angles of ΔTVX in order from smallest to largest.

Example 3Order Triangle Side Lengths

List the sides of ΔABC in order from shortest to longest.

Answer: AC, AB, BC

The angles from smallest to largest are B, C, and A. The sides opposite these angles are AC, AB, and BC, respectively. So, the sides from shortest to longest are AC, AB, BC.

Example 3List the sides of ΔRST in order from shortest to longest.

A. RS, RT, ST

B. RT, RS, ST

C. ST, RS, RT

D. RS, ST, RT

Example 4Angle-Side Relationships

HAIR ACCESSORIES Ebony is following directions for folding a handkerchief to make a bandana for her hair. After she folds the handkerchief in half, the directions tell her to tie the two smaller angles of the triangle under her hair. If she folds the handkerchief with the dimensions shown, which two ends should she tie?

Answer: So, Ebony should tie the ends marked Y and Z.

Example 4

A. A and DB. B and FC. C and ED. A and B

KITE ASSEMBLY Tanya is following directions for making a kite. She has two congruent triangular pieces of fabric that need to be sewn together along their longest side. The directions say to begin sewing the two pieces of fabric together at their smallest angles. At which two angles should she begin sewing?