A name given to the angle which measures exactly 90 degrees.

A quadrilateral with 4 equal sides and two sets of equal angles.

Working out the original amount from an increased or decreased value.

Represents the whole group.

A number which cannot be divided by a divisor.

A straight-sided 2D shape where all sides and angles are the same.

Example: A Square. 

A quadrilateral with 2 sets of equal parallel sides and 4 right angles.

Key Rectangle Topics: Area and Perimeter. 

Make the denominator an integer. This is used in the topic of Surds, where they want the answer without a surd in the denominator.

A number which can be calculated by dividing two integers.  All fractions are rational numbers.

A measure of how spread out the data is. It is calculated by finding the difference between the largest and smallest values. It is not an average but is usually calculated at the same time.