So, you have made it to the third in our difficult series of Eleven Plus maths quizzes on perimeter and area – give yourself a pat on the back for making it this far! In your exam you will have to work out the perimeter and area of 2D shapes, like squares, along with the surface area and volume of 3D shapes, like cubes. This quiz will help you practice.
While we are on the subject of shapes, here are the names of some lesser-known ones:
Don’t worry – you won’t need to know all of these - but if you can remember them all, they may come in useful at some point.
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The area of a right-angle triangle = (base × height) ÷ 2.
(16 x 12) ÷ 2 = 192 ÷ 2 = 96 cm2 |
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3D shapes do have an area, which we call 'surface area'.
A cube has six faces, each of which is a square, so to find its surface are we work out the area of one face and then multiply by 6 4 x 4 x 6 = 96 cm2 |
If you double the area of a circle, the radius is decreased fourfold (divided by 4). Conversely, if you decrease the radius of a circle by dividing it by 4, the area is halved
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The surface area of a cube = height x height x 6 (because it has 6 faces). However, the surface area of a cuboid is length x height x 6. We do not know the length of this cuboid, so we cannot answer the question.
Make sure you don’t confuse cuboids with cubes! |
The length of the perimeter of a regular polygon is found by multiplying the length of one of its sides by the number of sides. Decagons have ten sides, so 7 x 10 = 70 cm
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The volume of a cube = length3:
2 x 2 x 2 = 8 cm3. Make sure you don’t confuse cubed with squared! |
If you double the width of a square, its area quadruples (times by 4). Here’s the proof:
Square A: 5 x 5 = 25 Square B: 10 x 10 = 100 |
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The formula for the area of a circle is ?r2. As you know, the radius is half the diameter, so the area of this circle will be:
3.142 x (20 ÷ 2)2 = 3.142 x 102 3.142 x 100 = 314.2 cm2 |
It’s the side opposite the right-angle
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(63 ÷ 2) + (10 x 2) = 31.5 + 20 = 51.5 cm