3 D S H A P E S - Kamal Banat Math | Enjoy Mathing · 03/09/2013 · Name: _____ Topic: Worksheet #...

of 16 The Baptist School WS 8 Teacher: Kamal Banat

The Baptist School Subject: Math

Name: ______________________ Topic: Worksheet # 8

Grade: 8th Grade Date: . ,

3 D S H A P E S

Plan and elevation

When architects design buildings, they have to do 2D drawings to show what the building will look

like from each side. These drawings are called plans and elevations.

The view from the top is called the plan.

The views from the front and

sides are called the elevations.

Question

Can you sketch what the plan and elevations of this shape would look like?

Answer

Plan Front elevation Side elevation


Names of solids

Prisms

and

pyramids

A prism is a 3D shape which has a constant cross section - both ends of the solid are the same

shape and anywhere you cut parallel to these ends gives you the same shape too.

A pyramid has sloping sides that meet at a point.

Nets

Some 3D shapes, like cubes and pyramids, can be opened out and unfolded into a flat shape. The

unfolded shape is called the net of the solid.

Here are some 3D shapes and their nets.

3D shapes and their nets

Tetrahedron


Getting nets right

A net has to be able to fold up into the 3D shape. Look at these shapes. All of them are nets of a

cuboid. See if you can see why they would fold up into a cuboid.

Nets of a cuboid


Getting nets wrong

Look at these shapes. They are not true nets. See if you can see why they wouldn't fold up into a

cube.

Untrue nets

Using isometric paper

We can use isometric paper to draw 3-D shapes:


The vertical lines are This 3cm × 3cm × 3cm cube has been drawn using the dots as guides.

always vertical, but the horizontal lines are drawn at angles.

Sample question

Use isometric paper to draw a cuboid with a length of 6cm, a width of 3cm and a height of 2cm.

Click through the slideshow below to see how to draw a cuboid with these dimensions.

How to draw a cuboid


Examination style questions

1

The diagram is an accurate net for a solid shape.

Write down the geometrical name for this solid shape.

Answer ................................................

2

Write down the name of the solid that can be made from the net shown in the diagram.

Answer..........................................


3 I join six cubes face to face to make each 3-D shape below.

Then I join the 3-D shapes to make a cuboid.

Draw this cuboid on the grid below.


4 Each shape below is made from five cubes that are joined together.

Complete the missing diagrams below..


5 Look at the two triangular prisms.

They are joined to make the new shape below.

Complete


6

The solid shown is a cuboid with length 4 cm, width 2 cm and height 3 cm.

(a) Draw an accurate net of the cuboid on the grid below.

(b) Using your net, calculate the total surface area of the cuboid

.

Answer(b)...................................cm2


7 The net of a solid is drawn accurately below.

Write down the special name for

(a) the triangles shown on the net,

Answer(a) .................................................

(b) the solid.

Answer(b) .......................................

8

The diagram shows a triangular prism of length 7 cm.

The cross-section is an equilateral triangle of side 4 cm.

Complete an accurate net of the prism.

One rectangular face has been drawn for you.


9 The diagram shows a prism.

The lengths are in centimetres.

Part of an accurate net of the prism is drawn below.

Complete the net.

3 D S H A P E S - Kamal Banat Math | Enjoy Mathing · 03/09/2013 · Name: _____ Topic: Worksheet #...

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