In KS2 Maths as children advance to Year Five their knowledge of shapes will increase. By now they should know the names of the different 2D shapes from the circle to the decagon, and also many of the 3D shapes. They should also be able to recognise an equilateral, a right angle and an isosceles triangle and will now be taught about scalene and obtuse triangles and congruent shapes.

A circle and a triangle are both shapes. Did you know it is said that only a genius can draw a perfect circle? Have a go and see if you are a genius! There are various types of triangles, like Isosceles, scalene or equilateral, depending on the size of their angles.

Do you know the difference between an oblong and a rectangle? Can you tell an isosceles from a scalene triangle? See how much you remember about shapes by playing this quiz.

1.

What is an octahedron?

3D shape with octagon faces

3D shape with 8 faces

2D shape with 8 sides

2D shape with 8 angles

Remember that 'octa' means 8 and that 'hedron' means a 3D shape

2.

What is the shape of the faces of a regular octahedron?

Square

Octagon

Hexagon

Triangle

A regular octahedron would have equilateral triangles as each of its 8 faces

3.

Which of these shapes is **not** a quadrilateral?

Oblong

Rectangle

Pentagon

Square

Pentagons have 5 sides - all the other shapes have just 4

4.

What is an oblong?

A rectangle that is not a square

A rectangle that is a square

A quadrilateral that is not a square

A quadrilateral that is a square

A rectangle is a quadrilateral where all four sides are right angles

5.

What is the name given to polygons with all the sides and angles equal?

Irregular polygons

Regular polygons

Isosceles polygons

Equilateral polygons

Irregular polygons are where the sides are not equal

6.

What is a triangle with no equal sides and no equal angles called?

Isosceles

Equilateral

Scalene

Right angled

Scalene comes from the Greek word for "unequal"

7.

If you cut a triangular prism in half, what shape would the new face be?

Circle

Triangle

Square

Hexagon

If you cut a triangle into two with a straight line, at least one of the two pieces will be a triange

8.

What is the name given to a triangle with an angle larger than 90^{o}?

Isosceles

Equilateral

Scalene

Obtuse

Do you remember that angles between 90^{o} and 180^{o} are called obtuse angles?

9.

How do we know if two triangles are congruent?

If they both have the same three sides

If they both have a right angle

If they both have the same size angles

If they both have two sides the same

If one shape can become identical to another by using turns, flips or slides but without changing the size, then the two shapes are congruent

10.

What is the name given to the distance from one edge of a circle to the other through the centre?

Radius

Circumference

Tangent

Diameter

The diameter is twice the radius