Answer:
4. 73
5. 40°
Explanation:
The sum of the angles in a triangle is 180°. The sum of angles in a linear pair is 180°.
4. 45° +62° + k° = 180°
... 107 +k = 180 . . . . . collect terms, divide by °
... k = 180 -107 = 73 . . . . . subtract 107
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5. ∠STR = ∠SRT = 20°
... ∠STR +∠STU = 180°
... 20° + 4x = 180°
... 4x = 160° . . . . . . . . subtract 20°
... x = 40° . . . . . . . . . . divide by the coefficient of x