1. 6.1/6.2 Triangle Inequalities and Congruence 2. A student has an average score of 73 on five tests this semester. It is later discovered that one of the tests was graded incorrectly and the score should have been 91 instead of 81. What is the correct average of the five tests? A.74 B.75 C.76 D.83 Learning Objective: to determine if a triangle can be formed given 3 side lengths, to describe the 3 rd side, given 2 sides, and to identify congruent polygons and their corresponding parts. 1. B 8 C 55 What is the height of trapezoid ABCD? A.2 units B.3 units C.4 units D.6 units C B A 14 D

2. Notes Learning Objective: to determine if a triangle can be formed given 3 side lengths, to describe the 3rd side, given 2 sides, and to identify congruent polygons and their corresponding parts Triangle Inequality Theorems – A C B *The sum of the lengths of 2 sides of a triangle is greater than the length of the 3 rd side. *One side of a triangle is longer than a 2 nd side if and only if the angle opposite the 1 st side is larger than the angle opposite the 2 nd side.

3. EX 1 – A gardener wants to make a triangular garden. He has 23 feet of fence with which to form the perimeter of the garden. Can the gardener make a garden with the given side lengths? Learning Objective: to determine if a triangle can be formed given 3 side lengths, to describe the 3rd side, given 2 sides, and to identify congruent polygons and their corresponding parts a. 3 ft, 5 ft, 15 ft? Can’t be done! b. 8 ft, 7 ft, 8 ft?c. 3 ft, 11 ft, 9 ft? Shortcut??

4. Learning Objective: to determine if a triangle can be formed given 3 side lengths, to describe the 3rd side, given 2 sides, and to identify congruent polygons and their corresponding parts EX 2 – a. What do you know about the length of ? Sooo, UW must be between 3.7 and 12.3 b. Sketch 3 possible shapes of CKC p. 281

5. Learning Objective: to determine if a triangle can be formed given 3 side lengths, to describe the 3rd side, given 2 sides, and to identify congruent polygons and their corresponding parts Congruent Polygons – Same size and shape! B D A H G O *Polygons are congruent iff all corresponding parts are congruent *when naming congruent polygons, list corresponding angles in order!

6. Learning Objective: to determine if a triangle can be formed given 3 side lengths, to describe the 3rd side, given 2 sides, and to identify congruent polygons and their corresponding parts EX 3 – S F D G T R E R N M Q P 120° 125° 100° 10 7 (y-55)° 3w+1 Find the missing variables

7. HW – p. 282 #1-19 odd, p. 289 #1-9, 12-15 Out – How can you use the names of congruent polygons to determine the congruent sides? Summary – I have a question about… POW!!