Question

(LOOK AT IMAGE)

The sides of a regular 12-sided polygon have been extended to make a star, as shown below.
Calculate the size of angle x.
Give your answer in degrees (°). ​

Answer 1

Answer: 120

Explanation:

The interior angle of the 12-sided polygon is

`(180(12-2))/(12)=150^(\circ)`

So, if we consider the triangle with angle x, two of its angles are each
`30^(\circ)` since they are supplementary to the interior angle of the 12-sided polygon.

Therefore, as angles in a triangle add to 180 degrees, x=120.