A circle has a radius of 9 cm. Find the perimeter of the semi-circle. Leave

A central angle has a measure of 42O. What is the measure of the inscribed angle that subtends it?

All [answer] have dihedral symmetry.

A central angle has a measure of 82O. What is the measure of the inscribed angle that subtends it?

Consider the equation of a line given by

Consider the equation of a line given by 

Which describes an edge to edge tiling?

Which describes a chord?

Consider a polygon with n = [a] sides. What is the sum of the interior angles? Enter just the numeric value below. Do NOT include the unit of measurement. 

An inscribed  angle has a measure of 82O. What is the measure of the central angle that subtends it?