Everything Maths Grade 10

area of one prism side=bhp

= 20 42

=840 cm^2

Because the base triangle is equilateral, each side of the prism has the same area. Therefore the surface area
for each side of the prism is 840 cm^2.

Step 3: Calculate the total surface area of the object

total surface area=area of base of prism+area of sides of prism+area of exposed faces of pyramid

=

(

100

p

3

)

+ 3 (840) + 3 (133)

=3092,2 cm^2

Therefore the total surface area (of the exposed faces) of the object is 3092,2 cm^2.

VISIT:

This video shows an example of calculating the volume of a complex object.

See video:2GSVatwww.everythingmaths.co.za

Exercise 13 – 5:

1.The figure below shows a sphere. The radius of the sphere isr=8 units. Determine the volume of the

figure. Round your answer to two decimal places.

8

2.The figure here is a cone. The vertical height of the cone isH=7 units and the slant height ish=7,28

units; the radius of the cone is shown,r=2 units. Calculate the volume of the figure. Round your

answer to two decimal places.

7,k8

7

2

448 13.3. Right pyramids, right cones and spheres