Two squares of area 1 and 4 are inscribed in their own triangle and placed as shown. What fraction is coloured?
Author: Rik D. Tangerman
Turning tables
Two squares share a vertex. What fraction of the area is the overlap region?
The observatory dome
A semicircle with a radius, a chord and an altitude. What is the angle?
The hanging door
Two congruent rectangles support a third rectangle. What fraction is blue?
The PowerPoint
A point lies 8 from the centre of a circle of radius 6. The angle α is variable. What’s the maximum triangle area?
The kids windmill
Six congruent equilateral triangles placed inside a regular hexagon. What fraction is coloured?
Tall and wide
An equilateral triangle inscribed in a square. What’s the proportion of the red to the blue area?
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Who’s afraid of red, yellow and blue?
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The balance sheet
A unit square and a parallelogram. What’s the area of the latter?