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The snowman mansion

A square and a half square are stacked in order to form a house-shaped quadrilateral. Inside two circles are closely packed. What’s the angle between the tangency points?

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Intermediate

Balancing balls

Two touching circles are placed on top of a right triangle. What’s the angle between the chords connecting the tangency points?

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Intermediate

The marble box

Two marbles of sizes π and 4π are enclosed in a rectangular box. What is the total area of the box?

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Beginner

Moon over mountains

A rectangular frame encloses two congruent equilateral triangles and a unit circle. What is difference between width and height of the rectangle?

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Intermediate

The Pentagon peaches

Five equally sized peaches are closely packed in a pentagon-shaped box. Their midpoints are the vertices of a smaller pentagon. What fraction is shaded?

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Intermediate

An Egyptian sunset

A semicircle touches a large equilateral triangle (area equals 9) at its apex and a smaller adjacent equilateral triangle (area equals 1) at its base as shown. What is the total red area?