Multiple choice

AB, BC and CD are three consecutive sides of a regular polygon. If $\angle$ BAC = $20^{\circ}$, Find its each exterior angle

  1. $20^{\circ}$
  2. $30^{\circ}$
  3. $40^{\circ}$

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a regular polygon, triangle ABC is isosceles with AB = BC. Angle BAC = 20, so angle BCA = 20. Angle ABC = 180 - 40 = 140. The interior angle is 140. The exterior angle is 180 - 140 = 40.

AI explanation

In a regular polygon, triangle ABC is isosceles with AB = BC, making angle BAC equal to angle BCA, which are both 20 degrees. The interior angle B is 180 - 20 - 20 = 140 degrees. An exterior angle is supplementary to the interior angle, so it measures 180 - 140 = 40 degrees.

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