Two touching circles and a common tangent. Three triangles are formed by tangency points and centres. What is the area of the green triangle X in terms of areas A and B?
Tag: triangle
The folded napkin
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?
Twin peaks
A rectangle with three line segments. What is the proportion yellow : red?
Pyramidion
A triangle containing a semicircle and an equilateral triangle. What fraction is golden?
Triple dice
An equilateral triangle with three congruent squares. What’s the angle α?
Paper hat II
Two overlapping congruent right triangles. If |AB|=15 and |BC|=7, what is the total area?
En garde
An isosceles triangle with two altitudes dividing each other in segments of length 4 and 5. What is the total triangle area?
Distant peaks
Two isosceles triangles and a right angle. What is the proportion green : gold?
The Lion King II
A regular hexagon and three squares. What is the proportion yellow : brown?
The eye mask
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?