Page 218 - Maths Skills - 7

216 Maths

MAPPING THROUGH VISUAL ESTIMATION
As we know, estimation is the process of arriving at an approximate answer
to a question. In Geometry, estimate about space through visualization. Let us
understand it through the following example.

In the figure, small cuboidal boxes are stacked in a larger rack of cuboidal shape.
Can you estimate the total number of smaller boxes that can be fitted in the rack?
Here, we do not need to measure the dimensions of the rack. As seen in the Fig.,
2 boxes can be kept along the breadth, 3 along the height and 5 along the length.
Therefore, 30 boxes can be stacked in the rack.
Visual processing is a key skill in solving real-life problems. For example, in medical profession physicians take
a sample of blood, tissue or body fluids to be representative of the body as a whole and analyze it to check the
infections. Interior designers also require these skills, to excel in their field. Let’s solve some example now:

Let’s Attempt

Example 1: How many cubes are there in Fig.
Solution: There are 5 squares along the lengths, 3 squares along the
breadth and 2 squares along the height. Clearly, 5 × 3 × 2 = 30
cubes are stacked in the Fig.
Example 2: Draw the top, side and front views of the following figures:

(i) (ii)

Solution: The top, side and front views are as follows:

(i) (ii)
Top
Side Front

Exercise 13.1

1. Identify and write the geometrical name of the following.

(i) (ii) (iii) (iv) (v) (vi) (vii) (viii)