1. MATHS
NAME – KUMARI ADITI
CLASS – 7D , ROLL NO. – 23
SUBMITTED TO : SUBMITTED BY:
GITA MAM KUMARI ADITI
2. 3D Shapes
An object which occupies space is called a solid . A solid figure has three
measurements , each called a dimension ; they are length , breath and height or
depth. So, they are called three-dimensional objects or, in short, 3-D figures . Cube,
Cuboid, Cylinder, Cones etc., are 3D figures .
Some 3D Shapes – e.g., cuboids, cubes, prisms, pyramids-are made of polygonal
plane surfaces , each of which is called a face. Two faces meet at an edge . An edge is
a line segment. Edges meet at a vertex. Some other 3D shapes- like cones, cylinder,
spheres, - have curved faces; they may or may not have plane faces, edges and
vertices.
3. Cuboid
A cuboid is a solid bounded by six
rectangular faces. The adjacent faces are
perpendicular to each other and the opposite
faces have the same dimensions. The sides of
all the rectangular faces are called the edges
of cuboid . A cuboid has twelve edges . The
vertices of the rectangles are the vertices of
the cuboid . A cuboid has eight vertices.
4. Cube
A cube is a solid bounded by six square faces.
It is a special type in which all edges are
equal. So, it too has twelve edges and eight
vertices.
5. Sphere
The adjoining figure represents a sphere . It
has only one face, which curved. It has neither
any edge nor any vertex.
