Shape

Triangles

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Triangles have three sides. There are many different types of triangles:

Equilateral triangle

• 3 equal sides

• 3 equal angles of 60°

Isosceles triangle

• 2 equal sides

• 2 equal angles

Scalene triangle

• No equal sides

• No equal angles

Right-angled triangle

• One of its angles is a right angle (90°)

Quadrilaterals

Quadrilaterals have four sides. Here are some special quadrilaterals:

Square

• 4 equal sides

• 4 right angles

Rectangle

• 2 pairs of equal sides

• 4 right angles

Rhombus (squashed square)

• 4 equal sides

• Opposite sides are parallel

• Opposite angles are equal

Parallelogram (squashed rectangle)

• 2 pairs of equal sides

• Opposite sides are parallel

• Opposite angles are equal

Trapezium

• One pair of parallel sides of different lengths

Kite

• 2 pairs of equal sides next to each other

• No parallel sides.

Circles

All circles have a circumference, diameter and radius:

• The circumference is the distance all the way around a circle.

• The diameter is the distance right across the middle of the circle.

• The radius is the distance halfway across the circle. The radius is always half the length of the diameter.

Polygons

Polygons are shapes with many straight sides:

• Regular polygons have equal angles and sides of equal length.

• Irregular polygons have sides of different lengths.

Here are some common polygons:

Pentagons have 5 sides:

A regular pentagon

An irregular pentagon

Hexagons have 6 sides:

A regular hexagon

An irregular hexagon

A regular heptagon

An irregular heptagon

Octagons have 8 sides:

A regular Octagon

An irregular Octagon