Monday, 24 October 2016

Solutions to Word Problems (Pg 129 onwards)

Pg 129 - 134

1. 40 cm
2. 90 cm
3. 132 cm²
4. 1 + 1 + 1 + 1 = 4
    Ans: 4 m
    Even though the corners got cut away, each side still add up to be 1 m.

5. 85m²
6. 82 m (19 + 22 + 19 + 22)
7. 256 cm² (each side of the square is 24 - 4 - 4 = 18 cm)
8. 263 m²

Pg 135 - 140

1. 96 cm²
2. (a) 192 cm² (b) 58 cm
      *Take note that each side of the square is 2 cm

3. 39 cm
4. (a) 168 m² (b) $10920
    *For (a), find area of big rectangle then find area of small rectangle. The difference between them is the area of the foothpath.

5. $12 480
    Total area of the land is 156 m².

6. Since the length is 2 units, divide the whole rectangle into two equally.
    (72m² divided by 2 = 36 m²)  
    It forms 2 squares. Each square's area is 36 m². The length of each side is therefore 6 m.
    The breadth is therefore 6 m.
   

Pg 141 - 142

1. The 2 pieces were not said to be equal. 
    List down a table of all the possible perimeters of square:

2. If 2 breadths make 1 length, let each breadth be 1 unit, then 1 length = 2 units.
    The perimeter of the figure is then 10 units.
    80 cm ÷ 10 = 8 cm (1 unit)
    figure's breadth --> 8 cm x 2 = 16 cm
    figure's length --> 8 cm x 3 = 24 cm 
    24 cm x 16 cm = 384 cm2