Exercise 1.2 - Chapter 1 Geometry Term 3 5th Maths Guide Samacheer Kalvi Solutions - SaraNextGen [2024-2025]

Updated On May 15, 2024

By SaraNextGen

Ex $1.2$
Question $1 .$
The length of the side of each square is given below. Find its area.
(i) 10 metres
(ii) $5 \mathrm{~cm}$
(iii) 15 metres
(iv) $16 \mathrm{~cm}$
Answer:
(i) 10 metres
Area of the square $=$ Length of a side $\times$ length of side $=10 \times 10=100$ sq.m
(ii) $5 \mathrm{~cm}$
Area of the square - Length of a side $\times$ length of side $=5 \times 5=25$ sq.cm
(iii) 15 metres
Area of the square $=$ Length of a side $\times$ length of side $=15 \times 15=225 \mathrm{sq} . \mathrm{m}$
(iv) $16 \mathrm{~cm}$
Area of the square $=$ Length of a side $\times$ length of side $=16 \times 16=256$ sq.cm
 

Question $2 .$
Find the area of the following rectangles.
(i) length $=6 \mathrm{~cm}$ and breadth $=3 \mathrm{~cm}$

(ii) length $=7$ in and breadth $=4$
(iii) length $=8 \mathrm{~cm}$ and breadth $=5 \mathrm{~cm}$
(iv) length $=9 \mathrm{~m}$ and breadth $=6 \mathrm{~m}$
Answer:
(i) length $=6 \mathrm{~cm}$ and breadth $=3 \mathrm{~cm}$
Area of the rectangle $=$ Length $\times$ breadth
$=6 \mathrm{~cm} \times 3 \mathrm{~cm}=18 \mathrm{~cm}^{2}$
(ii) length $=7$ in and breadth $=4$
Area of the rectangle $=$ Length $\times$ breadth
$=7 \mathrm{~cm} \times 4 \mathrm{~cm}=28 \mathrm{~cm}^{2}$
(iii) length $=8 \mathrm{~cm}$ and breadth $=5 \mathrm{~cm}$
Area of the rectangle $=$ Length $\times$ breadth
$=8 \mathrm{~cm} \times 5 \mathrm{~cm}=40 \mathrm{~cm}^{2}$
(iv) length $=9 \mathrm{~m}$ and breadth $=6 \mathrm{~m}$
Area of the rectangle $=$ Length $\times$ breadth
$=9 \mathrm{~m} \times 6 \mathrm{~m}=54 \mathrm{~m}^{2}$

Question $3 .$
If the cost of 1 sq.m of a plot is $₹ 800$, then find the total cost of the plot that is $15 \mathrm{~m}$ long and $10 \mathrm{~m}$ breadth.
Answer:
Area of plot $=$ length $\times$ breadth $15 \times 10=150$ sq.m
Cost of 1 sq.m of a plot of land $=800$ rupees
Cost of a plot of land $=150 \times 800=1,20,000$ rupees.

Question $4 .$
The side of a square is $6 \mathrm{~cm}$. The length of a rectangle is $10 \mathrm{~cm}$ and its breadth is $4 \mathrm{~cm}$. Find the perimeter and area of both the square and rectangle.
Answer:
Perimeter of a square $=4 \times$ length of a side $=4 \times 6 \mathrm{~cm}: 24 \mathrm{~cm}$
Area of a square $=$ length of a side $\times$ length of a side
$=6 \times 6=36 \mathrm{~cm}^{2}$
Perimeter of a rectangle $=2 \times$ length $+2 \times$ breadth
$\begin{aligned}
&=2 \times 10+2 \times 4 \\
&=20+8=28 \mathrm{~cm}
\end{aligned}$
Area of a rectangle $=$ length $\times$ breadth
$=10 \times 4=40 \mathrm{~cm}^{2}$

Question $5 .$
What will be the labour cost of laying the floor of an assembly hall which is $14 \mathrm{~m}$ long and $10 \mathrm{~m}$ breadth if the cost of laying is 60 per sq.m?
Answer:
Area of a rectangle $=$ length $\times$ breadth
$=14 \times 10=140 \mathrm{~cm}^{2}$
Cost of laying 1 sq.m $=60$ rupees
Cost of laying the floor $=140 \times 60=8400$ rupees