RS Aggarwal Class 6 Math Nineteenth Chapter Three-Dimensional Shapes Exercise 19 Solution
SOLID – An object that has a shape and size is called a solid.
CUBOID – Solids such as a wooden box, a match box, a brick, a book, an almirah, etc., are all in the shape of a cuboid.
FACES – A cuboid has six rectangular faces.
EDGES – Two adjacent faces of a cuboid meet in a line segment, called an edge of the cuboid. A cuboid has 12 edges.
VERTICES – Three edge of a cuboid meet at a point, called a vertex. A cuboid has 8 vertex.
CUBE – A cuboid whose length and height are equal is called a cube.
CYLINDER – Objects such as a circular pillar, a circular pipe, a test tube, a circular storage tank, a measuring jar, a gas cylinder, a circular powder tin, etc., are in the shape of a cylinder.
SPHERE – An object which is in the shape of a ball is said to have the shape of a sphere.
CONE – Objects such as an ice-cream cone, a conical tent, a conical vessel, a clown’s cap, etc., are in the shape of a cone.
TRIANGULAR PRISM – A solid whose lateral faces are rectangular and the bases are congruent triangles, is called a triangular prism.
PYRAMID – A solid whose base is a plane rectilinear figure and whose side faces are triangles having a common vertex, called the vertex of the pyramid.
SQUARE PYRAMID – A solid whose base is a square and whose side faces are triangles having a common vertex is called a square pyramid.
TRIANGULAR PYRAMID – A solid whose base is a triangle and whose side faces are triangles having a common vertex is called a triangle pyramid.
Mark (√) against the correct answer in each of Q.1 to Q.6.
(1) A cuboid has
Ans: (c) length, breadth and height
(2) A dice is an example of a
Ans: (c) cone
(3) A gas pipe is an example of a
Ans: (d) cylinder
(4) A football is an example of a
Ans: (c) sphere
(5) A brick is an example of a
Ans: (b) cuboid
(6) An ice-cream cone is an example of a
Ans: (d) none of these
(7) Fill in blanks:
(i) An object that occupies space is called a solid.
(ii) A cuboid has 6 faces, 12 edges and 8 vertices.
(iii) The opposite faces of a cuboid are identical.
(iv) A sphere has no vertex and no edge.
(v) All the faces of a cube are identical.
(vi) A square pyramid has 4 lateral triangular faces and 8 edges.
(vii) A triangular pyramid has 3 triangular lateral faces and 6 edges.
(viii) A triangular prism has 6 vertices, 3 rectangular lateral faces, 2 triangular bases and 9 edges.
(8) Give examples of four objects which are in the shape of:
(a) A cone = Ice-cream cone, clown’s cap, conical tent, conical vessel
(b) A cuboid = A brick, a book, a chalk box, a match box.
(c) A cylinder = Circular pillar, circular pipe, measuring jar, test tube