Geometry is a word we use in maths. It means the study of shapes. In this, the second of our Easy Eleven Plus maths quizzes on Shapes, we look at some of the terms we use in geometry, like vertex, polygon, radii and perimeter, for example.

The format of this quiz is a little bit different to what you’d normally expect in maths. We’ll be giving you the definition of a word and asking you to find the term we are describing. It’s the sort of thing you’d find in an English exam, with one small difference – all the words we ask you for are terms used in geometry to describe shapes and their properties.

Even if you do not know some of the words, you will probably be able to work out the answers by using logic and reason to eliminate any red herrings. Just take your time and be sure you understand the question before you choose your answer.

Once you have got all ten answers right, why not move on to the next quiz? The more you practice, the better you will understand shapes. Good luck!

1.

Which word describes a 3-D shape made from polygons joined at their edges?

Pentagon

Polyhedron

Heptagon

Polygon

The word is made up from the Greek words for “Many faces”. Polygons are 2-D shapes and their name means “Many angles”

2.

Which word describes the amount of space inside a solid or 3-D shape?

Area

Perimeter

Volume

Circumference

Measurements of volume are always cubic (e.g. cm^{3}). Area is the space covered by a 2-D shape, or the surface of a 3-D shape, and is always measured in units squared (e.g. cm^{2})

3.

Which word describes a triangle whose sides are of equal length?

Isosceles

Right-angled

Equilateral

Scalene

The clue is in the name – equilateral means “equal sides”. Their corners also have equal angles of 60^{o}

4.

Which word describes the distance from the centre of a circle to its edge?

Diameter

Circumference

Radius

Sector

A circle’s radius is half its diameter. Circumference is the distance around a circle’s edge, and a sector is a part of a circle between to different radii (radii is the plural of radius)

5.

Which word describes a point where three or more edges meet on a 3-D shape?

Facet

Edge

Face

Vertex

Think of a vertex as a corner – cubes have 8 of them. Facet is another name for a face on a 3-D shape

6.

Which word describes an angle greater than 180^{o} but less than 360^{o}?

Acute

Right

Obtuse

Reflex

Acute angles are less than 90^{o}, right angles are equal to 90^{o} and obtuse angles are between 90^{o} and 180^{o}

7.

Which word describes a 2-D shape with three or more straight sides?

Polygon

Dodecahedron

Tetrahedron

Circle

Tetrahedrons are triangular pyramids and dodecahedrons are solids with 12 flat faces. Circles, though 2-D shapes, are not polygons

8.

Which word describes a 3-D shape with straight parallel sides and a circular or oval cross section?

Cuboid

Cylinder

Pyramid

Prism

Cylinders are a type of prism – but not all prisms are cylinders

9.

Which word describes a quadrilateral with one pair of parallel sides?

Trapezium

Parallelogram

Rhombus

Kite

Parallelograms have two sets of parallel sides. A rhombus is a parallelogram whose sides are the same length, while kites might not have any parallel sides at all - though they do have two pairs of equal-length sides

10.

Which word describes two lines next to each other with the same distance between them?

Parallel

Horizontal

Perpendicular

Vertical

Horizontal lines run parallel to the horizon and vertical lines run at right-angles to the horizon (up and down). Perpendicular lines run at right-angles to another defined plane (any line)