The ratio between the exterior angle and the interior angle of a regular polygon is 2 : 3 . Find the number of sides of the polygon.
Exterior angle= 2x, interior angle = 3x. Sum of them--> 2x+3x=180 deg --> x= 36 deg So, exterior angle = 2*36= 72 deg We know that each exterior angle of a regular polygon = 360 deg/n, (n= number of sides) So, 360 deg/ n=72 deg --> n=5
A twelve pointed star is made by extending the sides of a regular 12-sided polygon (a dodecagon). What is the measure of the grey angle?
If lengths of sides AB, BC and AC of a right angle triangle are in a geometric progression, what is the ratio between AC and AB?
A regular hexagon with side length 2 has semicircles constructed in its interior of each side. What is the shaded area inside the hexagon not covered by the semicircles?