A triangle with two cevians. What is d/c-b/a?
Categories
Fun with flags
Categories
The last wave
A square containing a quarter circle, a semicircle and a circle. What is the proportion blue : green?
Categories
The tightrope dancer
A circle containing an isosceles and two equilateral triangles. What is the proportion orange : blue?
Categories
The hidden pyramid
A triangle with an inscribed equilateral triangle. If areas A and B add up to C, what are the proportions A : B : C?
Categories
The chess board
A square is divided by six line segments. What fraction is brown?
A unit circle with an inscribed square and four semicircles. What’s the sum of the semicircle areas?
Categories
The Olympic bowl
A parabola is tangent to the equal sides of an isosceles triangle in its equal vertices. Another tangent is drawn as shown. Prove that the red line segments are congruent.
Categories
As above, so below
A semicircle, a square, a triangle and two circles. A centre and a tangency point are highlighted. Prove that the circles are congruent.
Categories
Down to earth
Two equilateral triangles share a vertex. What is the proportion red : green?
Categories
The sand heap
Two squares share a vertex. Three other vertices form a triangle, of which one side length is given. What is its area?