2 Given the diagram below What is the measure of Zd What is
Solution
Well, d and 75 form a linear pair of angles
 They add to 180
 So, d + 75 = 180
 d = 180 - 75
 d = 105
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In that triangle on the top right, we have two angles, 30 and 105
 Other angle, e = 180 - 105 - 30
 e = 75- 30
 e = 45
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Left most triangle :
 65 + 90 + a = 180
 a = 180 - 90 - 65
 a = 90 - 65
 a = 25
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a = b ---> vertical opp angles
 We get a =25
 So, b = 25
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Bottom right triangle
 b + c + 75 = 180
 25 + c + 75 = 180
 c + 100 = 180
 c = 180 - 100
 c = 80
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a + f + e = 180 ---> linear triplet of angles
 25 + f + 45 = 180
 f + 70 = 180
 f = 180 - 70
 f = 110

