Think about relation of corners and edges.

Look at the outer surface and count the number of sides.

Think about the shape of T.V. screen.

Count the number of corners of each shape.

Recognize the two different shape in the solid.

Think about the shape of triangle and rectangle only.

Count all the straight line in the picture.

Count the number of sides of this signboard.

Count the number of sides of the shapes given in the options.

Think about the edges of the square.