17.
Solution
(a) T. S. A. = Area of the 2 triangles +
Area of rectangle 1 + Area of rectangle 2
+ Area of rectangle 3
= 2 (½ x 6 x 8) + (6 x 5.5) + (10 x 5.5) + (8 x 5.5)
= (2 x 24) + 33 + 55 + 44
= 48 + 33 + 55 + 44
Therefore T. S. A. = 180cm²
(b) V = Base area x height = 24 x 5.5 V = 132cm³
6cm
8cm
5.5cm
10cm
A triangular prism has a base in form of a right-angled triangle, with sides
6cm, 8cm and 10cm. If the height of the prism is 5.5cm, sketch the prism
and calculate,
(a) its total surface area,
(b) its volume.
Example
20.
Find the volume of the following prisms.
9 m2
V = 9 x 5 = 45 m3
8 cm2 7 mm2
5 m
4 cm
10
mm
20 mm2
10
mm
30 m2
2½ m 40 cm2
3 ¼ cm
V = 8 x 4 = 32 cm3 V = 7 x 10 = 70 mm3
V = 20 x 10 = 200 mm3 V = 30 x 2½ = 75 m3 V = 40 x 3¼ = 130 cm3
1 2 3
4 5 6