Test: Shapes Around Us - Class 4 MCQ

Euler's formula states that for any convex polyhedron, the relationship between the number of faces (F), vertices (V), and edges (E) can be expressed as:

• F + V - E = 2

For a cube:

• It has 6 faces.
• It has 8 vertices.
• It has 12 edges.

Now, substituting these values into the formula:

• F + V - E = 6 + 8 - 12
• This simplifies to 2.

Thus, the value of F + V - E for a cube is 2.

A pentagon is defined as a five-sided polygon with five equal angles. 

A sphere is characterized by its perfectly round shape with no edges or corners, making it unique among geometric shapes. 

A triangular pyramid has 4 corners, also known as vertices, where each triangular face meets.

A cone has one flat circular face and one curved surface that tapers to a point. 

When a net consisting of six squares is folded, it forms a cube.

The flat surface of a 3D shape is called a face.

• A face is any flat surface on a 3D shape.
• It can be a triangle, rectangle, or any other polygon.
• Each solid shape is made up of multiple faces.
• For example, a cube has six square faces.

A triangular prism consists of 5 faces: two triangular bases and three rectangular lateral faces.

To determine the number of vertices for the given shape -

• Count the corners or points where the edges meet. These are the vertices.

• From the image, you can identify 8 vertices.

A cylinder has a net made up of two circular bases connected by a curved surface. This shape is widely used in everyday objects like cans and pipes etc. 

A sphere has 1 face. This face is smooth and curved, with no edges or corners.

• The face of a sphere is continuous.
• It does not have any flat surfaces.
• All points on the surface are equidistant from the centre.

An obtuse angle is any angle that measures greater than 90 degrees but less than 180 degrees.

A circle is flat with no thickness, making it a 2D shape.

A cube has 12 edges, which are the lines where its square faces meet. 

A rectangle is defined as a quadrilateral with opposite sides that are equal in length and four right angles (90 degrees).