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A polygon has 15 sides.

(b) If the sum of seven of the exterior angles is 200°, find the sum of the
eight interior angles not adjacent to these exterior angles.

A polygon has 15 sides. (b) If the sum of seven of the exterior angles is 200°, find-example-1
User BlueMonk
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1 Answer

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13 votes

Answer:

  • The sum of the eight interior angles not adjacent to these exterior angles is 1280°.

=================

Given

  • A 15-sided polygon with sum of 7 exterior angles 200°.

To find

  • The sum of the 8 interior angles, remote to known 7 angles.

Solution

We know that:

  • sum of all exterior angles of a polygon is 360°.
  • sum of each interior and exterior angle pair is 180°.

So the sum of the 8 exterior angles is:

  • 360° - 200° = 160°

Sum of both interior and exterior angles of 8 angles:

  • 180°×8 = 1440°

Sum of those 8 interior angles is:

  • 1440° - 160° = 1280°
User Noxxer
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