Answer to problem 5 is A) WU = ZX.
Notice how the angle U is between WU and VU. Similarly, angle X is beween ZX and XY
The order is very important. The angles must be between the two pairs of sides.
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Answer to problem 6 is C) 15/17.
Use the pythagorean theorem to find the hypotenuse AC to be 17 units. Then take the ratio of the adjacent and hypotenuse to get the answer.
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Answer to problem 7 is choice C
Use the rule cos(90-x) = sin(x) where x = 72-a