A triangle cut by a line and four parallel line segments. Prove that green = red.
Above the line
A triangle cut by a line and four parallel line segments. Prove that green = red.
A circle with its centre and three triangles consisting of chords and radii. Express area X in terms of A, B and α.
Two triangles are placed as shown. What is the angle α?
A triangle with its incircle and a cevian. What is red : yellow?
A couloured triangle and rectangle with extended sides and two circles. Prove that the triangle and the rectangle have equal areas.
Four triangles in a rectangle. The three red triangles have equal areas. What is blue : red?
Three congruent squares and an equilateral triangle. What is blue : orange?
An equilateral triangle with a cevian and two inscribed circles. What is yellow : red?
A triangle, its circumcircle, circumcentre and two altitudes. What’s the angle α?
A cyclic quadrilateral has side lengths a, c, j, and k. Three segments drop perpendicularly to two sides and one diagonal of the quad, forming the green and purple triangles between them. What is the ratio purple/green, in terms of a, c, j, k?
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