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1. Estimate the size of each angle below. Then determine if it is acute, right, obtuse, or straight. 170 30 90 100 180
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Find the measure of the following angles: a. EDF = ___________ b. ADE = ___________ c. CDF = ___________ d. FDC = ___________ 35 145 100
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3. Complete the statements based on the markings in the picture. a. LJK ___________ b. LMP ___________ c. JIH ___________ MJI GHQ PIG
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In the picture, m MRT = 133 . a.Is MRT acute, right or obtuse? b.Write an equation and solve for x. c. Find the measure of MRN. obtuse 6g – 11 = 133g = 24 46
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5. Construct a copy the following angle so that the angle is doubled. Be sure to leave all construction markings.
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6. Construct the angle bisector of the angle. Be sure to leave all construction markings.
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7. Find the perimeter and area of the figure. Label all side lengths. Show work! P = ___________ A = ____________ 8 4 5 48
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7. Find the perimeter and area of the figure. Label all side lengths. Show work! P = ___________ A = ____________ 8 4 5 48 88 – 20 68
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8.Examine the figure graphed on the axes at right. a.What happens when you rotate this figure about the origin 45 ? 90 ? 180 ? b. What other angles could the figure at right be rotated so that the shape does not appear to change? It matches up 135 , 225 , 270 , 315 , 360
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Scoring Your Homework Count how many problems you missed or didn’t do 0-1 missed = 10 2-3 missed = 9 4-5 missed = 8 6-7 missed = 7 8-9 missed = 6 10-11 missed = 5 12-13 missed = 4 14-15 missed = 3 16-17 missed = 2 18-19 missed = 1 20-21 missed = 0
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2.2 What’s the Relationship? Pg. 6 Complementary, Supplementary, and Vertical Angles
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2.2 – What's the Relationship?________________ Complementary, Supplementary, and Vertical Angles In Chapter 1, you compared shapes by looking at similarities between their parts. For example, two shapes might have sides of the same length or equal angles. In this chapter you will examine relationships between parts within a single shape or diagram. Today you will start by looking at angles to identify relationships in a diagram that make angle measures equal.
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2.10 – ANGLE RELATIONSHIPS When you know two angles have a certain relationship, learning something about one of them tells you something about the other. Certain angle relationships come up often enough in geometry that we given them special names.
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76 90 – 76 = 14
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62 180 – 62 = 118
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23 157 23 157
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23 157 23 157 CEB
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AEC and DEB
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54 126 54 126
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b. Based on your observations, write a conjecture (a statement based on an educated guess that is unproven). Start with, "Vertical angles are...“ Vertical angles are _________________. congruent
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2.12 – PROVING VERTICAL ANGLES CONGRUENT The last problem used what is called inductive reasoning to show that vertical angles are congruent. We are now going to start to use deductive reasoning to prove that all vertical angles are congruent, no matter what the angles measure. Below you are given the steps in order to prove that vertical angles are congruent. Your job is to explain why each statement is true. Match the reasons with the given statements.
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A. Both add to 180 B. Straight angles add to 180 C. Subtract y from both sides D. Straight angles add to 180 Straight angles add to 180 Both add to 180 Subtract y from both sides
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90 40 50 40
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2.14 –ANGLES RELATIONSHIPS In the problems below, you will use geometric relationships to find angle measures. Start by finding a special relationship between some of the angles, and use that relationship to write an equation. Solve the equation for the variable, then use that variable to find the missing measurement.
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Angle Relationship: __________________ Equation: __________________________ PNM = ____________________________ supplementary x + 152 = 180 x = 28 28
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Angle Relationship: __________________ Equation: __________________________ FGH = ____________________________ congruent 4x – 5 = 3x + 2 x = 7 23
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Angle Relationship: __________________ Equation: __________________________ DBC = ____________________________ complementary 3x + 3 = 90 x = 29 36
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Angle Relationship: __________________ Equation: __________________________ QPM = ____________________________ supplementary 2x + 28 = 180 x = 76 76
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2.15 – SUMMARY Discuss each different type of angle measurement: right, complementary, straight, supplementary, congruent, and vertical. What is their relationship? Are they equal or add to something? Draw a picture of each.
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RightComplementary One 90 angle Angles that add to 90
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StraightSupplementary One 180 angle Angles that add to 180
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CongruentVertical Angles with same degree Opposite angles that are congruent P Q R S 1 2
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