Selina Concise Class 7 Math Chapter 18 Recognition of Solids Exercise 18 Solution

Selina Concise Class 7 Math Chapter 18 Recognition of Solids Exercise 18 Solution

EXERCISE 18

(1) (i), (ii) and (v)

(4)

Faces a 5 20 6
Vertices 6 b 12 d
Edges 12 9 c 12

(i) a + 6 – 12 = 2

⇒ a – 6 = 2

⇒ a = 2 + 6 = 8

(ii) b + 5 – 9 = 6

⇒ b – 4 = 6

⇒ b = 6 + 4 = 10

(iii) 20 + 12 – c = 2

⇒ 32 – c = 2

⇒ – c = 2 – 32

⇒ – c = – 30

⇒ c = 32

(iv) 6 + d – 12 = 2

⇒ d – 6 = 2

⇒ d = 2 + 6 = 8

(6) (i) cube

(ii) Cuboid

(9) Given, 1 cm = 12 km

The distance between two cities = 13.8 cm

∴ Actual distance between two cities = (13.8 × 12) km = 165.6 km

Get next Exercise 19 solutions click here

Leave a Reply

Your email address will not be published. Required fields are marked *