Categories
Beginner

The green kimono

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

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?

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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?

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Beginner

The square peg

A square is fitted into an equilateral triangle as shown. What fraction is shaded?

Categories
Beginner

The askew envelope

In a square, an interior point is drawn with an angle to the top vertices of 120°. What’s the angle between the chords formed by the two arcs centered in these vertices?

Categories
Beginner

The fishing net

Two squares and two equilateral triangles. What fraction is hatched?

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Beginner

The broken window

A square is divided into triangles and quadrilaterals as shown. What fraction of the square area is covered by the shaded triangle?

Categories
Beginner

The tilted brick

A rectangle is covering a square such that they share a diagonal and the top side of the square is divided in half as shown. What fraction of the square is covered by the rectangle? And what fraction of the rectangle is covered by the square?

Categories
Beginner

The tilted hourglass

In a square, a diagonal and a line segment cross at the center. They delimit a tilted hourglass. What fraction of the square is shaded?