Answer:
4. 143°
5. x=32°, exterior angle=134°
Explanation:
The relation of interest in these two questions is ...
an exterior angle of a triangle is equal to the sum of the remote interior angles.
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4.
The exterior angle is u°. The opposite (remote) interior angles are a right angle (90°) and one marked 53°. The above relation tells you ...
u° = 90° +53°
∠u = 143°
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5.
In this figure, the external angle is marked (4x+6)°, and the opposite internal angles are x° and 102°. Our relation between these tells us ...
(4x +6)° = x° +102°
3x = 96 . . . . . . . . . . . . divide by °, subtract x+6
x = 32 . . . . . . . . . . divide by 3
∠x = 32°
(4x+6)° = (4(32) +6)° = 134°