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. $(There\ may\ be\ multiple\ answers\ for\ these!)$
"

AcademicMathematicsNCERTClass 7

Given: some shadows of some 3-D objects, when seen under the lamp of an overhead projector.

To do: To identify the solid(s) that match each shadow. 

Solution:

We know that:

  • A spherical solid casts a shadow of a circular shape.
  • A cylindrical solid casts a shadow of a linear or rectangular shape.
  • A cuboidal solid casts a shadow of a rectangular shape.
  • A conical solid casts a shadow of a triangular shape.
  • A cubical solid casts a shadow of a square shape.
Therefore, we can say:

$(i)$ A ball or sphere will give a shadow of a circle.

$(ii)$ A cube-shaped object such as dice will give the shadow of a square.

$(iii)$ An ice-cream cone or a birthday cap will give the shadow of a triangle.

$(iv)$ A book or a cuboid shape object will give the shadow of a rectangle.
raja
Updated on 10-Oct-2022 13:40:01

Advertisements