Categories
Intermediate

Sticky corners

Two equilateral triangles and several line segments. What is red : yellow?

Categories
Intermediate

Vanishing point II

Six squares and four coloured triangles. What is red : blue : yellow : green?

Categories
Beginner

Two-story A-frame house

The slanted lines are perpendicular, and the one in the bottom story bisects the angle. Show that red equals green, so the stories have the same height.

Categories
Beginner

Angle versus height

What is the ratio orange/green?

Categories
Advanced

Alien eye

Two quarter-circles fit inside a square, and five circles fit inside the overlapped region, centred. What is the ratio of the (straight line) segment lengths red to blue? (The segments connect to points of tangency.)

Categories
Intermediate

Ball of yarn

A cyclic hexagon has concurrent cross diagonals. What is the ratio of the product of the orange sides compared to the product of the purple sides. (ace:bdf).

Categories
Beginner

Domino day II

Two large congruent rectangles share a vertex and contain two coloured rectangles. What is red : blue?

Categories
Intermediate

Giant’s shoulder II

Three equilateral triangles share three vertices. What is blue : red?

Categories
Beginner

Pythagoras times three

Three squares on a grid. What is the ratio of the areas red : green : purple?

Categories
Advanced

The open roof

A regular hexagon with two line segments at right angles. What is the minimum of yellow : red?