A square sheet of paper is folded symmetrically from a corner. If the fold length is 4, what is the area of the triangle formed by the other three corners?
A rectangle with three line segments. What is the proportion yellow : red?
A triangle containing a semicircle and an equilateral triangle. What fraction is golden?
An equilateral triangle with three congruent squares. What’s the angle α?
Two overlapping congruent right triangles. If |AB|=15 and |BC|=7, what is the total area?
An isosceles triangle with two altitudes dividing each other in segments of length 4 and 5. What is the total triangle area?
Two isosceles triangles and a right angle. What is the proportion green : gold?
A regular hexagon and three squares. What is the proportion yellow : brown?
A right triangle with its inscribed circle. Two cevians are drawn through the circle centre. What is the circle area in terms of triangle areas A and B?
An equilateral triangle with an altitude. Two of its sides form the radii of the circular sector. What fraction of the area is covered by the red circle?