SOLUTION: In a regular polygon each exterior angle is 150 degrees greater than each exterior. Calculate the number of sides

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Question 1100967: In a regular polygon each exterior angle is 150 degrees greater than each exterior. Calculate the number of sides

Found 2 solutions by KMST, ikleyn:
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
The question should state
"In a regular polygon each interior angle is 150 degrees greater than each exterior angle".
An exterior angle is the change of direction needed at each vertex to go around the polygon.
It is supplementary to the adjacent interior angle,
meaning that both of them add up to 180%5Eo .
For example, here is a regular hexagon, with an interior angle and an exterior angle labeled as such:


In a regular polygon,
if each interior angle is 150 degrees greater than each exterior angle,
all exterior angles measure x degrees,
and all interior angles measure 150%2Bx degrees,
150%2B2x=180 , 2x=30 and x=15.
If you change direction by 15 degrees at each vertex,
one whole turn going around the polygon, adding up a 360%5Eo turn,
will require 360%2F15=24 changes of direction at 24 vertices,
and the polygon has highlight%2824%29 sides.

The teacher wants you to remember that the sum of the interior angles of a polygon with n sides is %28n-2%29%2A180%5Eo ,
but without remembering,
you would intuitively know that for all polygons,
the sum of all exterior angles is 360%5Eo ,
and it makes calculations faster/easier in this case.

Answer by ikleyn(52786) About Me  (Show Source):
You can put this solution on YOUR website!
.
In a regular polygon each highlight%28cross%28exterior%29%29 interior angle is 150 degrees greater than each exterior. Calculate the number of sides.
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Step 1     (Finding the measure of an exterior angle)

Exterior + Interior   = 180°

E        + I          = 180°

E        + (E + 150°) = 180°

2E       + 150°       = 180°

2E                    = 180° - 150° = 30°  ====>  E = 30%2F2 = 15°.

Step 2     (Finding n, the number of sides)

For any convex polygon, the sum of its exterior angles is  360°.


It gives in our case

n*E = 360°,   or  n*15° = 360°,  which implies  n = 360%2F15 = 24.


Answer. The number of sides/vertices is 24.