**48cm**

Area of rectangle is 128cm²

So use algebra to solve (remember area of rectangle = LxW)

2x * x = 128 (where 2x = length and x = width. Use 2x given length is twice width)

3x=128

2x²=128

x²=64

**x=8**

So perimeter = (8*4 for the length + 8*2 for the width) = **48cm**

**72cm**

(15 * 4) + (3*4) = 60 + 12

**C**

The answer would be the highest factor of both 8 & 20 from the options since each tile is square. The answer to this is 4

**Area = 200cm²**

- If 2x long as wide, then need to calculate each side
- Double length v width means length is 20cm and width is 10
- Area = 200cm²

**a) 160cm**

**b) 168cm²**

**a) 0.33cm²**

Overlap is 1/3rd of a triangle. So area if full would be 1×1 = 1cm. So answer is 1/3rd of this

**b) 12.25cm²**

2 full shaded squares. In addition, 1.5 other shaded squares. So 3.5 x 3.5

**462cm**

Large Triangle = 16cm * 3 (all sides same as its equilateral). So 48cm

Middle Triangle = 7cm * 3 triangles * 3 sides (7 small triangles of 1cm each on the horizontal base tells us its a 7x7x7 triangle). So 63cm

Next size Triangle of which there are 3 = 3cm * 3 triangles * 3 sides = 27cm. There are 3 of them so 27cm

Smallest triangle = 36 small triangles all of 1cm per side. So 3cm *36 triangles * 3 sides = 324cm

Total of all of these is 48 + 63 + 27 + 324

**64cm**

Perimeter = 14+3+4+6+7+2+17+11

**a) 30°**

180 – Australia – Africa = 180-90-60

**b) 1/8**

45/360 = 9/72 = 1/8

**c) 30**

180/1 * 60/360 = 180*1/6 = 30

**d) 1000**

Degrees for Europe = 180 – USA = 180-45 = 135

1600 * 225/360. Simplified this is 1600 * 45/72 = 15/24

1600/1 * 15/24

**1/4**

4 parts of 16 shaded = 4/16 = 1/4

**a) 1200mm²**

Area of rectangle = LxW = 60mm x 20mm

**b) 40 triangles**

2 Triangles will joined together have dimensions of LxW = 12mmx5mm. So they form a rectangle

Therefore, in 60mm across, you get 5 “blocks” of 2 triangles. And you can go to a height of 4 blocks

So in total 5 * 4 blocks = 20 blocks. 2 triangles per block so 40 triangles

**c) 1200mm**

Perimeter of 1 triangle = 12+5+13=30mm

Total number of triangles = 40

Total Perimeter =1200mm

**d) 1.2m**

10mm = 1cm

100cm = 1m

1000mm = 1m

**Area of 1 rectangle = 15 x 5 = 75cm²**

**30cm**

- If Length is 11cm more than width, need possible combinations to give multiple of 60
- So this could be 30×2 or 15×4. Or several others
- 15×4 is the only combination that works and this gives a length 11cm more than the width
- So perimeter is 11cm + 4cm + 11cm + 4cm

**20cm²**

Its 10cm length x 2cm height. So 20cm²

**80cm**

- 9 identical squares with area of 144 means square has an area of 16cm
- Each square must be 4×4
- Number of sides showing on the shape above if you count all the way around as a perimeter is 20
- So perimeter is 80cm

**96 tiles**

3metres long and 4m wide = 12m² area

You will get 12 tiles in the width from 25cm tiles (3metres = 300cm. 300cm/25 = 12 tiles)

Across you will get 8 tiles in the length from 50cm tiles ( 4metres = 400cm/50cm – 8 tiles)

12 x 8 = 96 tiles

**a) 64cm²**

Perimeter = 32. Therefore, each side is 8cm

Area = 8 x 8 = 64

b) 48cm²

**20 students**

- Work on basis 6 students = 30°
- Therefore, 2 students = 10°
- So, 100° = 20 students

**Approximately 40°**

An acute angle

**65°**

- Triangle = 180°
- 180 – 50 – 130
- 130/2 = 65

**8m**

- Area is LxW
- So working backwards, 72=9xW
- Rearrange. W=8

**72 stickers**

- 80/10 = 8
- 45/5 = 9
- 8 * 9 = 72