find the measure indicated. Assume that the lines which appear to be tangent are tangent. Part 4
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The angle between the two tangents drawn from an external point to a circle and the angle subtended by the line segment joining the points of the contact at the Centre are supplymentary,
So,
15.) let the unknown angle be x
=》x + 55° = 180°
=》x = 180° - 55°
=》
[tex] \boxed{x = 125°}[/tex]
16. let the unknown angle be n
=》n + 80° = 180°
=》n = 180° - 80°
=》
[tex] \boxed{n = 100°}[/tex]
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Answer:
15) 125°
16 100°
Step-by-step explanation:
The short arc where two tangents intersect a circle, and the angle where the tangents meet are supplementary.
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15) ? = 180° -55° = 125°
16) ? = 180° - 80° = 100°
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Additional comment
The quadrilateral formed by the tangents and the radii to the points of tangency has a total interior angle measure of 360°. The angles where the radii meet the tangents are 90°, so the sum of the external angle and the central angle is 360° -90° -90° = 180°. That is, the external angle and the central angle are supplementary.