Page 214 - Maths Skills - 7

212 Maths

cuboid. You may show TU, QU and VU as dotted lines as shown in Fig. 7. A cuboid has 8 vertices, 6 faces and
12 edges.
T W
T W
P S P S P S

U V U V
Q R Q R Q R
Fig. 5 Fig. 6 Fig. 7
Isometric Sketches G
Oblique sketch represents the depth of an object, but it doesn't show the exact
measurement of the sides. Hence, for that we draw isometric sketch. Isometric
sketches are drawn on dotted or isometric sheets. The measurements of an F C
isometric sketch of a 3D object are in proportion to the measurements of the
solid shape being sketched.
Here is an isometric sketch of a cube.
D
Let us draw an isometric sketch of a cuboid having dimension: 5 cm, 4 cm and E B
3 cm by following these steps:

A

Isometric sketch of a cube
Step 1: The length of the front face of the cuboid is 5 cm. We take the C
distance between two dots as 1 cm and draw a line AB joining the
dots to represent the edge 5 cm long. The width is 4 cm; therefore B
lines AD and BC are drawn across four dots to represent 4 cm long. D
A line through C and D is then drawn to have the complete face
proportional to the given dimensions. A

Step 2: The height of the cuboid is 3 cm. Therefore, AP, BQ, CR and DS R
are drawn through three dots to represent the height of 3 cm.
Q S
C
P
B
D

A

Step 3. Finally, PQ, QR, RS and SP are joined. We now have an isometric R
sketch of the cuboid, every face of which is proportional to the
corresponding faces of the given cuboid. Q
S
C

B P
D

A