Chapter 13: Fields and Fences

In order to find the length of the boundary of the shapes given in the figure –

– Take a thread.

– Now place the thread over the figure along the boundary.

– Cut the remaining thread, which is necessary to cover exactly the boundary of the figure.

– Measure the length of the thread.

– Do the same thing with all figures.

(a) We know that

Number of complete squares in figure A = 1

Number of complete squares in figure B = 2

Number of complete squares in figure C = 3

Number of complete squares in figure D = 2

(b) Figure A is the shape which covers the least number of squares which is 1.

(c) Figure C is the shape which covers the most number of squares which is 3.

The different shapes, which are formed by placing the thread on the squared sheet, are as follows:

(a) 9 complete squares are present in figure A, 3 complete squares are present in figure B, 6 complete squares are present in figure C, and 4 complete squares are present in figure D.

(b) The biggest shape is figure A.

(c) The smallest shape is figure B.

(d) We can measure the boundary of each shape by placing thread along them.

NCERT Textbook Page No. – 154

The shapes done by joining two squares are given below.

Here four types of shapes can be done by joining two squares.

The shapes done by joining three squares are given below.

Here seven types of shapes can be done by joining three squares.

NCERT Textbook Page No. – 155