A rectangle with several line segments. What’s the angle α?
Categories
Right angle II
Tag: rectangle
Categories
The purple straw
Three unit squares and a rectangle. What is the purple area?
Categories
Steering left
Two overlapping rectangles and a semicircle centred in their common vertex. What’s blue : orange?
Categories
Boxing the circles
Four semicircles packed in a rectangle, tangent at four points. Show that the blue semicircle intersects the top horizontal line as shown. (The red circles are the same size.)
Categories
Dome city umbrella
Fixed point C, at distance x from the center of a unit semicircle. The rectangle varies with angle α from 0 to 90 degrees. What is the radius of the arc traced by the corner point G. Is the arc concentric with the green arc?
Two congruent tangent circles and a rectangle with an extended side. What is yellow : red?
Categories
Torn between
Two rectangles, a triangle and its incircle. What is red : blue?
Categories
The menhir cycle
Two squares and a rectangle. Prove that the four red points are concyclic.
Categories
Squaring up
Three squares, two of which are congruent, a rectangle and a line segment. What is the angle α?
Categories
Secured gold coin
A rectangle containing a circle with two tangents. Prove that the red line segments are parallel.