Categories
Beginner

Mouth to mouth

What is the ratio of the blue and yellow lines?

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Beginner

Equal rights

Two squares sharing a vertex. Two vertices are connected by a line segment. What is yellow : green?

Categories
Beginner

Running man

What is the area of the coloured figure? Can you determine the area without counting the number of squares in each different-coloured shape?

Categories
Beginner

Tip of the veil

A square with two right angles. What fraction is yellow?

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Intermediate

Wheel of fortune

A unit square and a point on the inscribed circle. What is a2+b2+c2+d2?

Categories
Beginner

Peekaboo

Three congruent squares share two vertices while the upper sides coincide. What’s red : blue?

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Beginner

Guylines II

A square, two orthogonal axes and two angles. What’s the proportion α : β?

Categories
Beginner

Pac-Man pack

Four Pac-Men eat the corners of a square while four others stand guard. What fraction of the square is eaten?

Categories
Beginner

Le col bleu

A square with two line segments. What fraction is blue?

Categories
Intermediate

By coincidence

Three squares and a circle. Prove that the red point is on two squares and the circle.