Everything Maths Grade 10

x^2 = 3^2 +

(

8

2

) 2

x^2 = 3^2 + 4^2

= 25

)x=5 cm

)perimeter of triangle= 5 + 5 + 8

=18 cm

)area of large rectangle=perimeter of trianglelength

= 18 12

=216 cm^2

area of triangle=

1

2

bh

=

1

2

 8  3

=12 cm^2

Step 3: Find the sum of the areas of the faces

surface area=area large rectangle+ (2area of triangle)

= 216 + 2 (12)

=240 cm^2

Step 4: Write the final answer
The surface area of the triangular prism is 240 cm^2.

Worked example 4: Finding the surface area of a cylinder

QUESTION

Find the surface area of the following cylinder (correct to 1 decimal place):

10 cm

30 cm

424 13.2. Right prisms and cylinders