Question

The net of an isosceles triangular prism is shown here. What is the surface area, in square units, of the triangular prism?

94 units2
98 units2
129 units2
136 units2

Answer 1

To do this, find the surface area of each two-dimensional shape.

The two triangles have a combined area of 24.

The two rectangles have a combined area of 70.

The center rectangle has an area of 42.

Add them together to get 136 as your surface area.

Answer 2

Answer: Last option is correct.

Explanation:

Since we have given that

Dimension of central rectangle is 6 units by 7 units

So, Area of central rectangle is given by

`Length* breadth=6* 7=42\ sq.\ units`

Dimensions of upper and lower rectangle are as follows:

Length = 5 units

Breadth = 7 units

Area of upper and lower rectangle is given by

`2* length* breadth \\\\=2* 5* 7\\\\=70\ sq.\ units`

Similarly, dimensions of two triangles are as follows:

Height = 4 units

Base = 6 units

So, Area of two triangles is given by

`2* (1)/(2)* base* height\\\\=4* 6\\\\=24\ sq.\ units`

Hence, Total surface area of the net of an isosceles prism is given by

`42+70+24\\\\=136\ sq.\ units`

Therefore, Last option is correct.