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## Selina Concise Mathematics Class 8 ICSE Solutions Chapter 19 Representing 3-D in 2-D

**Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 19 Representing 3-D in 2-D**

### Representing 3-D in 2-D Exercise 19 – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.

If a polyhedron has 8 faces and 8 vertices, find the number of edges in it.

Solution:

Question 2.

If a polyhedron has 10 vertices and 7 faces, find the number of edges in it.

Solution:

Question 3.

State, the number of faces, number of vertices and number of edges of:

(i) a pentagonal pyramid

(ii) a hexagonal prism

Solution:

Question 4.

Verily Euler’s formula for the following three dimensional figures:

Solution:

Question 5.

Can a polyhedron have 8 faces, 26 edges and 16 vertices?

Solution:

Question 6.

Can a polyhedron have:

(i) 3 triangles only ?

(ii) 4 triangles only ?

(iii) a square and four triangles ?

Solution:

Question 7.

Using Euler’s formula, find the values of x, y, z.

Solution:

Question 8.

What is the least number of planes that can enclose a solid? What is the name of the solid.

Solution:

Question 9.

Is a square prism same as a cube?

Solution:

Question 10.

A cubical box is 6 cm x 4 cm x 2 cm. Draw two different nets of it.

Solution:

Question 11.

Dice are cubes where the sum of the numbers on the opposite faces is 7. Find the missing numbers a, b and c.

Solution:

Question 12.

Name the polyhedron that can be made by folding each of the following nets:

Solution:

Question 13.

Draw nets for the following polyhedrons:

Solution: