Fill in the blanks: The length and breadth of a rectangle are $12\ cm$ and $5\ cm$, respectively, then its diagonal is ________ $cm.$
Answer
The length and breadth of a rectangle are $12\ cm$ and $5\ cm$, respectively, then its diagonal is $13 \ cm$.
We have, Length of the rectangle $= 12\ cm$ and
Breadth of the rectangle $= 5\ cm$
Now, the diagonal of the rectangle $=\sqrt{(\text{Length})^{2}+(\text{Breadth})^{2}}$
$=\sqrt{12^{2}+5^{2}}$
$=\sqrt{144+25}$
$=\sqrt{169}$
$=13\text{cm}$
Fill in the blanks: The area of a rectangle is $120\ cm^2$, If the breadth is 6\ cm, then its length is _________.
Answer
The area of a rectangle is $120\ cm^2$, If the breadth is 6\ cm, then its length is $60m.$
We have,
Area of the rectangle $= 120\ cm^2$ and
Breadth of the rectangle $ = 6\ cm$
As, the length of the rectangle $=\frac{\text{Area}}{\text{Breadth}}$
$=\frac{120}{6}$
$=20\text{cm}$
Fill in the blanks: The perimeter of a square $16\ cm$, then its area is ________ $cm^2$.
Answer
The perimeter of a square $16\ cm$, then its area is $16 \ cm^2$.
As, the perimeter of the square $= 16\ cm$
So, the side of the square $=\frac{\text{Perimeter}}{4}$
$=\frac{16}{4}$ $=4\text{cm}$ Now, the area of the square = (Side $\times $ Side) $= 4 \times 4 = 16\ cm^2$
Fill in the blanks: The perimeter of a square whose area is $225m^2$ is ________.
Answer
The perimeter of a square whose area is $225m^2$ is 60 m.
As, the area of the square $= 225m^2$ So, the side of the square $=\sqrt{\text{Area}}$
$=\sqrt{225}$ $=15\text{m}$
Now, the perimeter of the square $= 4 \times $ Side $= 4 \times 15 = 60m$
Fill in the blanks: If the ratio between the length and perimeter of a rectangular plot is $1 : 3$, then the ratio between the length and breadth of the plot is _________.
Answer
If the ratio between the length and perimeter of a rectangular plot is $1 : 3$,
then the ratio between the length and breadth of the plot is 2 : 1.
Let the length of the rectangular plot be $x$ and its perimeter be $3x.$
As, the breadth of the rectangular plot $=\Big(\frac{\text{Perimeter}}{2}\Big)-\text{Length}$
$=\frac{3\text{x}}{2}-\text{x}$
$=\frac{3\text{x}-2\text{x}}{2}$
$=\frac{\text{x}}{2}$
Now, the ratio between the length and breadth of the plot $=\frac{\text{Length}}{\text{Breadth}}$
$=\frac{\text{x}}{\big(\frac{\text{x}}{2}\big)}$
$=\frac{2\text{x}}{\text{x}}$
$=\frac{2}{1}$
$=2:1$