Class 7 Maths

Solid Shapes

Exercise 15.3

Question 1: What cross-sections do you get when you give a (i) vertical cut (ii) horizontal cut

To the following solids: (a) A brick, (b) A round apple, (c) A die, (d) A circular pipe, (e) An ice cream cone

Answer: (a) Rectangle in both sections, (b) Circle in both sections, (c) A square in both sections, (d) Rectangle in vertical section and circle in horizontal section, (e) Triangle in vertical section and circle in horizontal section.

Exercise 15.4

Question 1: A bulb is kept burning just right above the following solids. Name the shape of the shadows obtained in each case. Attempt to give a rough sketch of the shadow.

shadow of solid shape shadow of solid shape shadow of solid shape

Answer: (i) Circle, (ii) Rectangle, (iii) Rectangle

Question 2: Here are the shadows of some 3 – D objects, when seen under the lamp of an overhead projector. Identify the solid (s) that match each shadow.

shadow of solid shape shadow of solid shape shadow of solid shape shadow of solid shape

Answer: (i) Spherical, (ii) Cube, (iii) Pyramid, (iv) Cuboid

Question 3: Examine if the following are true statements:

  1. The cube can cast a shadow in the shape of a rectangle.
  2. The cube can cast a shadow in the shape of a hexagon.

Answer: (a) True, (b) False