9514 1404 393
Answer:
10. A) 120°
11. D) 40°
12. D) 54°
13. A) 101°
Explanation:
The applicable rules of angles and arcs are ...
- the whole is the sum of the parts
- arcs of a circle total 360°
- an inscribed angle intercepts an arc of twice its measure
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10) Angles C and L intercept the same arc (DE) so will have the same measure.
15x = 16x -4
4 = x . . . . . . . . add 4-15x
arc DE = 2(15x) = 30(4) = 120 . . . degrees
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11) Arc VW is twice the measure of angle X, so ...
9x +8 = 2(5x)
8 = x . . . . . . . . . subtract 9x
∠VXW = 5x = 5(8) = 40 . . . degrees
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12) Arc EFG is twice the measure of angle W, so ...
70° +FG = 2(88°)
FG = 106° . . . . . . . . . subtract 70°
Arc FGW is twice the measure of angle E, so ...
106° +GW = 2(80°)
GW = 54° . . . . . . . . . . subtract 106°
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13) Arc ST is twice the measure of angle R. The sum of arcs is 360°.
RS +ST +TR = 360°
119° +2(70°) +TR = 360°
TR = 101° . . . . . . . . subtract 259°