Categories
Intermediate

The double flag

Three tangent circles and a common tangent. The three tangency points are shown. What is α + β?

Categories
Advanced

The door stop

A triangle with a cevian. What is α?

Categories
Beginner

Easing it down

Three squares share three vertices. What’s the angle α?

Categories
Intermediate

The pendulum

Two equilateral triangles share a side midpoint. What is the angle α?

Categories
Intermediate

Five to twelve

A square and a rectangle share two vertices. If the square has twice the area of the rectangle, what’s the angle α?

Categories
Advanced

The grazing shot

A parabola and its directrix in red. Two tangents intersect at a point on the directrix. What’s the angle α?

Categories
Intermediate

Worlds colliding

Two intersecting circles and a circle passing through both their centres and their intersection points. What’s the angle α?

Categories
Beginner

The parallax effect

Two intersecting circles with a triangle that passes through their centres and an intersection point. What’s the angle α?

Categories
Intermediate

Under the volcano

A square containing a right isosceles and an equilateral triangle. What’s the angle α?

Categories
Intermediate

The queen

A cyclic quadrilateral with extended sides and two tangents forming an angle γ. What is γ in terms of α and β?