Year 5 Maths · Measurement & Space
You are the park designer at Cretaceous Cove. Work out how much fencing each enclosure needs and how much ground space each dinosaur gets — using perimeter and area of rectangles.
Section 1 · Perimeter
By the end of this section I can calculate the perimeter of a rectangle and solve practical fencing problems — so I can order the right amount of fencing for each dinosaur enclosure.
Tick each one when you can do it without help.
The perimeter is the total distance around the outside of a shape. For a dinosaur enclosure, that is exactly how much fencing you need to build the boundary.
A rectangle has two pairs of equal sides. Add the length and the width, then double the total — because there are two lengths and two widths:
P = 2 × (length + width)
If the length is L and the width is W, the perimeter is 2 × (L + W). The unit is metres (m) because we are measuring length.
Check yourself
A Brachiosaurus enclosure is 9 m long and 5 m wide. How many metres of fencing are needed to go all the way around?
The park has 36 m of fencing for a rectangular Ankylosaurus enclosure. If the length is 10 m, what is the width in metres?
Use the grid below to build a rectangular enclosure. Each grid square represents 1 metre. Watch how the perimeter updates as you change the length and width.
Interactive · build a rectangle and read the perimeter
Check yourself
An Iguanodon enclosure has a perimeter of 30 m. If the length is 11 m, what is its width?
A square Velociraptor enclosure has sides of 8 m each. How much fencing is needed to surround it?
Section 2 · Area
By the end of this section I can calculate the area of a rectangle and solve practical space problems — so I can check each dinosaur has enough ground space in its enclosure.
Tick each one when you can do it without help.
The area is the amount of flat surface inside a shape — the ground space a dinosaur can actually roam on. For a rectangle, you can find it by counting 1-metre squares or by multiplying.
Multiply the length by the width. Each row has length squares, and there are width rows — so the total number of squares is:
A = length × width
Area is measured in square metres (m²) because we are counting squares that are 1 metre on each side.
Check yourself
A Parasaurolophus enclosure is 8 m long and 6 m wide. What area of ground space does it provide?
A Pachycephalosaurus needs 72 m² of space. If the enclosure is 9 m wide, what length must it be?
Two enclosures can have the same perimeter but different areas. The shape matters! Use the grid to see how the area changes as you adjust the dimensions — each filled square is 1 m² of dinosaur space.
Interactive · fill the enclosure and count the square metres
Check yourself
Two enclosures each have 24 m of fencing. One is 8 m × 4 m and the other is 6 m × 6 m. What is the larger area, in square metres?
A Carnotaurus enclosure is 12 m long and 7 m wide. What is its area in square metres?
Same Year 5 Maths outcomes, rebuilt around whatever your child is into this week - dinosaurs, Minecraft, horses, you name it.
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