What is the area of the entire figure (in terms of x) given that the segments AB, CD, EF,…, QR are all semicircle diameters, and the lengths decrease geometrically ( AB=2, CD = 2x, EF= 2x^2, GH = 2x^3,…)?
Tag: length
Double eclipse
Given green and blue discs, construct a red region so that for every ray leaving L stays in the blue region exactly as long as it does in the pink region. (Namely, KM = OL.)
Steam roller
Two intersecting circles. Express the lengths b and the common tangent d in terms of c (the distance between the centres) and the angles β and γ.
Pentagon pleasure
Two regular pentagons. The centre of the large one is a vertex of the small one. What is yellow : green?
Under the dome
Two semicircles with four squares and a yellow rectangle. What is the aspect ratio of the latter?
Pull the string
Two regular hexagons and a circumcircle. What is blue : red?
Antennas above and below
The triangle ABC has orthocentre H, so that HA is an antenna above the green hill. The rectangle BCDE is inscribed in the circumcircle (ABC). Show that HA = CD = BE.
Squaring a rectangle II
A square contains a red rectangle with an extended side. Prove that red=|AB||AC|+|BE||CD|. By Matthew Arcus.
Sticky corners
Two equilateral triangles and several line segments. What is red : yellow?
Median between sides
A triangle has sides a,b,c and the medians d,e,f ending at those sides, respectively. Given the lengths (a,b,f) construct the triangle. (Start with a triangle with side lengths determined in some manor from the given 3 lengths.)