Shapes Around Us (3D Shapes) — NCERT Solutions

Concept used: Every object around us resembles a 3D solid shape.

Matching guide:

• Drum / Tabla / Dholak → Cylinder (2 circular faces, 1 curved surface)
• Harmonium / Gift box / Chalk box → Cuboid (6 rectangular faces, 12 edges, 8 corners)
• Ball / Matka (rounded) → Sphere (1 curved surface, no edges, no corners)
• Ice cream cone / Funnel → Cone (1 circular face, 1 curved surface, 1 corner)
• Dice / Sugar cube → Cube (6 square faces, 12 equal edges, 8 corners)

Answer: Draw lines matching each instrument/object to its correct solid shape as described above.

(Note: Since the actual image is not visible, students should use the above matching guide with the objects shown in their textbook.)

Concept used:

• Stars are placed on each FACE of the shape.
• Ribbon stripes are placed on each EDGE of the shape.
• Pompom balls are placed on each CORNER of the shape.

Key facts about common 3D shapes:

Cube:

• Faces = 6, Edges = 12, Corners = 8
• Stars = 6, Ribbon stripes = 12, Pompom balls = 8

Cuboid (rectangular box):

• Faces = 6, Edges = 12, Corners = 8
• Stars = 6, Ribbon stripes = 12, Pompom balls = 8

Cylinder:

• Faces = 2 (flat circular faces) + 1 curved surface = 3 surfaces, Edges = 2 (curved), Corners = 0
• Stars = 2 (flat faces), Ribbon stripes = 2, Pompom balls = 0

Cone:

• Faces = 1 (flat circular face) + 1 curved surface, Edges = 1 (curved), Corners = 1
• Stars = 1, Ribbon stripes = 1, Pompom balls = 1

Sphere:

• Faces = 1 curved surface, Edges = 0, Corners = 0
• Stars = 0 (no flat face), Ribbon stripes = 0, Pompom balls = 0

Filled Table:

(Students should fill the table for the specific objects shown in their textbook using the values above.)

Concept used: Properties of 3D shapes — faces, edges, and corners.

Definitions:

• Face: A flat or curved surface of a 3D shape.
• Edge: A line where two faces meet.
• Corner (Vertex): A point where edges meet.

Complete Table:

Note: For a cone and cylinder, the 'curved surface' is counted as a face at the Class 2 level.

(Students should match the objects shown in their textbook to the correct row and fill accordingly.)

Concept used: Corners (vertices) are the pointed tips/meeting points of edges in a 3D shape.

No Corners (0 corners):
A. Ball (Sphere) — 0 corners
B. Tin can (Cylinder) — 0 corners
C. Bangle / Ring — 0 corners

One Corner (1 corner):
A. Ice cream cone (Cone) — 1 corner
B. Party hat (Cone) — 1 corner
C. Funnel (Cone) — 1 corner

Three Corners:
(Note: Common 3D shapes do not have exactly 3 corners. A triangular pyramid/tetrahedron has 4 corners. At Class 2 level, this may refer to a triangular prism or a shape made from clay/cardboard.)
A. Triangular prism — 6 corners (if this column means something else, students should refer to their textbook image)

Eight Corners (most likely the blank is 8):
A. Cube — 8 corners
B. Cuboid (box) — 8 corners
C. Brick — 8 corners

Answer: Fill in the names of objects from your surroundings that match the number of corners as described above.

Object with four faces: A Triangular Pyramid (Tetrahedron).

Steps:

1. Draw 4 equilateral triangles on a cardboard sheet (one large triangle with 3 smaller triangles attached to its sides — this is called a net).
2. Cut along the outer edges.
3. Fold along the inner lines.
4. Stick the edges together with glue or tape.

Result: You will get a 3D shape (triangular pyramid) that has 4 triangular faces.

Answer: A triangular pyramid has 4 faces, 6 edges, and 4 corners.

Object with one face: A Sphere (like a ball) has only 1 curved face.

Steps to make using clay/dough:

1. Take a ball of clay or dough.
2. Roll it between your palms to make it perfectly round.
3. You have made a sphere — it has only 1 curved surface (face), 0 edges, and 0 corners.

Alternatively, using cardboard:

1. Cut a circle from cardboard.
2. Roll it into a cone shape — but a cone has 2 faces.
3. The easiest way is to use clay to make a round ball (sphere).

Answer: A sphere has only 1 face (curved surface), no edges, and no corners.