Geometric Questions Answers

Geometry - Quant/Math - CAT 2008

Question 4 the day: October 7, 2002
The question for the day is from the topic of Geometry.

Each interior angle of a regular polygon is 120 degrees greater than each exterior angle. How many sides are there in the polygon?

(1)

6

(2)

8

(3)

12

(4)

3

Correct Answer - (3)

 

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Solution:

Let an exterior angle A^o. Then each interior angle will be 120 + A^o.
We know that in any regular polygon, the sum of an exterior and interior angle is always = 180^o.
Therefore, A + 120 + A = 180 => A = 30^o.

No. of sides of a polygon =  360  /  eachexterior angle = 360/30  = 12 sides.