Grade 12 - More exercises : answers.

Area and volume.

1.1
240
1.2
697,5
1.3
82,5
1.4
144
1.5
342
1.6
1 299,2
1.7
1 720,210
1.8
16,982
2.1
V = 33022,5   ;   SA = 7492
2.2
V = 300 763   ;   SA = 26 934
2.3
V = 4 590   ;   SA = 2188,645
2.4
V = 129,681   ;   SA = 123,899
2.5
V = 26 507,188   ;   SA = 5 466,085
3.1
A = 13,5
3.2
A = 11,142   ;   perimeter = 14,283
3.3
A = 335
3.4
A = 90 000   ;   perimeter = 1 600
3.5
A = 86,549   ;   perimeter = 36,850
4.1
a = √2, b = √3 and c = √4 = 2
The hypotenuse of the first triangle is √2. The hypotenuse of every following triangle is equal to
√(hypotenuse of previous triangle + 1)
4.2
√5 ; √6 ; √7
4.3
Perimeter = 6
4.4
Area of first triangle = 0,5; area of second triangle = 0,707 or 0,5√2 and
area of third triangle = 0,866 or 0,5√3
Total area of figure = 2,073
5.1
24,232
5.2
33,353
5.3
30,788
6.1
30,631
6.2
65,597
7.1
77
7.2
No, the ground close to the plastic cover can not really be used as the vertical workspace is too small.
7.3
211,665
8.
Remember that 1 000 litre is equal to 1 cubic metre. Change the 5 000 liter to 5 cubic metre.
Rectangular tank: possible measurements are width = 1,5 m, breadth = 1,5 m and height = 2,222 m.
Area of material = 17,832 square metre.
Cube: Measurements: each side = 1,710 m.
Area of material is 17,544 square metres.
Cylinder: Possible measurements are: diameter = 1,784 m and height = 2 m.
Area of material = 27,417 square metres.
  
To the top Exercise Grade 12 - exercises Grade 10 - exercises Grade 11 - exercises Home page