Two semicircles with diameters AB and DC are drawn inside rectangle ABCD and intersect at two points. AB=104 cm and BC=96 cm. Find the distance between the intersection points in cm.
An equilateral triangle, a square and a regular pentagon share vertices as shown. AK and HL are perpendicular to KL. Using the marked 21°,55°,39°, find the marked angle at E in degrees.
A regular polygon is divided into 18 congruent pentagons as shown; all sides of each pentagon are equal. If k,ℓ are the two largest angles of one pentagon, find k+ℓ in degrees.