Categories
Intermediate

The secret document

One corner of a rectangular piece of paper is folded back and forth to the opposite side. What is the proportion red : blue?

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Advanced

The sneak peek

A rectangle with given side lengths is folded back and forth such that the corner touches the opposite side as shown. What is the minimal shaded fraction?

Categories
Intermediate

Take five origami

Divide a rectangular piece of paper in five pieces of equal area. You only have a pair of scissors at your disposal, but you are allowed to make straight folds to guide you.

Categories
Intermediate

The kingsize bed

A rectangle with an inscribed right triangle. What is ac/bd?

Categories
Intermediate

The folded napkin

A square sheet of paper is folded symmetrically from a corner. If the fold length is 4, what is the area of the triangle formed by the other three corners?

Categories
Beginner

The bobline

A regular hexagon is folded back and forth along the dotted line. What fraction of the area is yellow?

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 folded sheet

A rectangular sheet of paper is folded in such a way that two equal angles are formed as shown. What fraction of the resulting quadrilateral is shaded?