Categories
Intermediate

The King’s chamber

A pyramid with a square base and sides that are equilateral triangles contains a cube. If the cube is taking maximum space as shown, what is the fraction of its volume to the pyramid’s volume?

Categories
Intermediate

The sundial statement

A triangle is formed by a circle radius and an external point. It is divided by the shown chord. What’s the proportion of the angles α and β?

Categories
Intermediate

The folded triangle

An equilateral triangle is folded with its left side at right angles with the base. What fraction of the total triangle is shaded?

Categories
Beginner

The green kimono

An equilateral triangle and three squares. What’s the angle?

Categories
Advanced

The wheelbarrow

A circle and two semicircles are nested as shown. What’s the proportion of their respective radii a : b : c ?

Categories
Beginner

The circus tent

A regular octagon is coloured as shown. What fraction of its area is red?

Categories
Advanced

The party hat

A cone has height 6 and base diameter 6. On it lie two points, one exactly halfway up, the other diametrically opposed at the base. What’s the shortest distance between these points going along the cone surface?

Categories
Beginner

The windshield wipers

A square and two rectangles, connected by two circular arcs, form a square. What is the proportion of the orange to the green area?

Categories
Intermediate

Velocipede II

Two circles of area π and 9π respectively are contained in a parallelogram. What’s its area?

Categories
Intermediate

The pyramid perspective

Two congruent pyramids placed at different distances from the observer appear as equilateral triangles in a square frame. If the closest one is at 100 meter, how far is the distant pyramid?