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7. Conjecture: m B = 2(m A). B. D. A. C. B. 30 . E. x. C. A. D. From HW # 6. Given:. 1. x = 15. Find the measure of the angle marked x. x. From HW # 6. x = 15. 2. A. D. B. C. 63 . 63. 41. 104. A. D. B. C. 63 . 63. 41. 104. A. D. B. C. 63 . .
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7. Conjecture: mB = 2(mA) B D A C
B 30 E x C A D From HW # 6 Given: 1. x = 15 Find the measure of the angle marked x.
x From HW # 6 x = 15 2.
A D B C 63 63 41 104
A D B C 63 63 41 104
A D B C 63 104
A D B C 63 41 76 104 63 D
14 C E F D B A
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. C D F A B E
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. Outline of proof: 1. A B (isosceles triangle theorem) C D F A B E
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. Outline of proof: 1. A B (isosceles triangle theorem) 2. AE EB (definition of midpoint) C D F A B E
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. Outline of proof: 1. A B (isosceles triangle theorem) 2. AE EB (definition of midpoint) 3. ADE and BFE are congruent right angles C D F A B E
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. Outline of proof: 1. A B (isosceles triangle theorem) 2. AE EB (definition of midpoint) 3. ADE and BFE are congruent right angles 4. ADE BFE (AAS) C D F A B E
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. Outline of proof: 1. A B (isosceles triangle theorem) 2. AE EB (definition of midpoint) 3. ADE and BFE are congruent right angles 4. ADE BFE (AAS) 5. DE EF and AD BF (CPCTC) C D F A B E
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. Outline of proof: 1. A B (isosceles triangle theorem) 2. AE EB (definition of midpoint) 3. ADE and BFE are congruent right angles 4. ADE BFE (AAS) 5. DE EF and AD BF (CPCTC) 6. DEF is isosceles (definition of isosceles ) C D F A B E
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. Outline of proof: 1. A B (isosceles triangle theorem) 2. AE EB (definition of midpoint) 3. ADE and BFE are congruent right angles 4. ADE BFE (AAS) 5. DE EF and AD BF (CPCTC) 6. DEF is isosceles (definition of isosceles ) 7. DC FC (subtraction post, AC – AD = BC – BF) C D F A B E
From HW # 6 5. In the diagram, triangle ABC is isosceles with base , E is the midpoint of , and . Prove that triangle DEF and triangle CDF are isosceles. Outline of proof: 1. A B (isosceles triangle theorem) 2. AE EB (definition of midpoint) 3. ADE and BFE are congruent right angles 4. ADE BFE (AAS) 5. DE EF and AD BF (CPCTC) 6. DEF is isosceles (definition of isosceles ) 7. DC FC (subtraction post, AC – AD = BC – BF) 8. CDF is isosceles. C D F A B E
From HW # 6 6. Think about how you would prove that the altitudes to the legs of an isosceles triangle are congruent.
7. Conjecture: mB = 2(mA) B D A C
Use Geometer’s Sketchpad to construct quadrilateral ABCD in which AB is parallel to CD and BC is parallel to AD.
A parallelogram is a quadrilateral with both pairs of opposite sides parallel. A square is a rhombus and a rectangle. Definitions A rhombus is a parallelogram with one pair of adjacent sides congruent. A rectangle is a parallelogram with one right angle.
bases legs A trapezoid is a quadrilateral with exactly one pair of sides parallel. An isosceles trapezoid is a trapezoid with the two non-parallel sides congruent. Base angles (there are two pairs)
HW #7 Fill in the chart (question 5) on the HW 7 handout. Begin work on the rest of the problems. You will have all period on Monday to complete it.