Class-8

Chapter-18,19

1)Write down the number of faces , edges and vertices of the following figures.

i)cuboid ii)cube iii) Triangular prism iv)Square pyramid v)Rectangular pyramid  

vi)Triangular pyramid vii) Square prism viii) Pentagonal prism.

2)Define Euler’s relations between the number of faces, number of edges and number of vertices for various 3 dimensionals figures.

3)Verify Euler s  relation for  a right prism having each of the bases a polygon of n sides.

4)Verify Euler’s relation  for a pyramid whose base is a polygon of n sides.

5) The area of a trapezium 576 sq cm. if the ratio of the parallel sides is 3:5 and the distance between the parallel sides is 12cm.find the two parallel sides.

6) The cross section of a canal is trapezium in shape. It is 15m wide at the top and 10m wide at the bottom and the area of cross section is 125sq.m find the depth of the canal.

7)Find the area of a regular hexagon of side 6cm.

8) Find the area of the polygon given in fig. 

 

 

 

 

 

9) Find the area of the following region given in the fig.