Question

20. Using Euler's formula find the unknown value:
FACES
VERTICES
(i)
20
12
EDGES
6
12
5
9
(iv)
5
5
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Answer 1

Answer:

Ncert solutions

Grade 8

Mathematics

Science

Chapters in NCERT Solutions - Mathematics , Class 8

Exercises in Visualising Solid Shapes

Question 7

Q7) Using Euler’s formula find the unknown.

Solution 7: (i) Faces-?,vertices-6,edges-12

Euler's formula: F+V–E=2

F+6–12=2

F=2+12–6=8

F=8

(ii) Faces-5,vertices-?,edges-9

Euler's formula: F+V–E=2

5+V–9=2

V=2+9–5=6

V= 6

(iii) Faces-20,vertices-12,edges-?

Euler's formula: F+v–E=2

20+12–E=2 ,

E=20+12–2

E=30