Quadrilaterals

There are 65 NRICH Mathematical resources connected to Quadrilaterals
Rabbit Run
problem

Rabbit run

Age
7 to 11
Challenge level
filled star filled star filled star

Ahmed has some wooden planks to use for three sides of a rabbit run against the shed. What quadrilaterals would he be able to make with the planks of different lengths?

Stellar Angles
problem

Stellar angles

Age
11 to 14
Challenge level
filled star empty star empty star
Weekly Problem 30 - 2013
What is the angle $x$ in the star shape shown?
Outside the Nonagon
problem

Outside the nonagon

Age
11 to 14
Challenge level
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Weekly Problem 44 - 2010
Extend two of the sides of a nonagon to form an angle. How large is this acute angle?
Folding Flowers 1
problem

Folding flowers 1

Age
7 to 11
Challenge level
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Can you visualise what shape this piece of paper will make when it is folded?
The Cyclic Quadrilateral
article

The cyclic quadrilateral

This gives a short summary of the properties and theorems of cyclic quadrilaterals and links to some practical examples to be found elsewhere on the site.