Tag: construction of line segment and circle of given radius

Questions Related to construction of line segment and circle of given radius

The centre of the circle circumscribing the square whose three sides are $3x+y=22,x-3y=14$ and $3x=y=62$ is:

  1. $\left( \dfrac { 3 }{ 2 } ,\dfrac { 27 }{ 2 } \right) $

  2. $\left( \dfrac { 27 }{ 2 } ,\dfrac { 3 }{ 2 } \right) $

  3. $(27,3)$

  4. $\left( 1,\dfrac { 2 }{ 3 } \right) $


Correct Option: B

A square is inscribed in the circle $x^2 + y^2 -2x +4y - 93 = 0$ with its sides parallel to the coordinates axes. The coordinates of its vertices are 

  1. $( - 6, - 9), \, ( - 6, 5), \, (8, - 9)$ and $(8, 5)$

  2. $( - 6, 9), \, ( - 6, - 5), \, (8, - 9)$ and $(8, 5)$

  3. $( - 6, - 9), \, ( - 6, 5), \, (8, 9)$ and $(8, 5)$

  4. $( - 6, - 9), \, ( - 6, 5), \, (8, - 9)$ and $(8, - 5)$


Correct Option: A

For each of the following, drawn a circle and inscribe the figure given.If a polygon of the given type can't be inscribed,write not possible.

  1. Rectangle.

  2. Trapezium.

  3. Obtuse triangle.

  4. non-rectangle parallelogram

  5. Accute isosceles triangle.

  6. A quadrilateral PQRS with $\overline {PR} $ as diameter.


Correct Option: A

In regular hexagon, if the radius of circle through vertices is r, then length of the side will be

  1. $\displaystyle \frac{2\pi r}{6}$

  2. r

  3. $\displaystyle \frac{\pi r}{6}$

  4. $\displaystyle \frac{r}{2}$


Correct Option: B
Explanation:

$\Rightarrow$   Radius of a circle is $r$.

$\Rightarrow$   In regular hexagon all sides are equal.
$\Rightarrow$   The regular hexagon has 6 equilateral triangles. The diameter of the circle is $2r$ in this case, will coincide with 2 equilateral triangles. So the side of the hexagon will be $r$.
$\therefore$   Length of side of hexagon is $r$.

When constructing the circles circumscribing and inscribing a regular hexagon with radius $3$ m, then inscribing hexagon length of each side is

  1. $1m$

  2. $2m$

  3. $3m$

  4. $4m$


Correct Option: C
Explanation:

When constructing the circles circumscribing and inscribing a regular hexagon with radius $3$ m, then inscribing hexagon length of each side is $3$ m.

The area of a circle inscribed in a regular hexagon is $100\pi$. The area of the hexagon is:

  1. $600$

  2. $300$

  3. $200\sqrt { 2 } $

  4. $200\sqrt { 3 } $

  5. $200\sqrt { 5 } $


Correct Option: D
Explanation:

Area of circle $=100\pi $
$\pi r^{2}=100\pi $
$r^{2}=100$
$r=10$
Now, a regular hexagon is made up of 6 equilateral $\bigtriangleup s $ of equal areas. Now, height of equilateral $\bigtriangleup  $ is equal to radius of circle.Therefore, ar. of 1 equilateral $\bigtriangleup=\dfrac {1}{2} $ x base x height
$\Rightarrow \dfrac {\sqrt{3}}{4}a^{2}=\dfrac {1}{2}a*10\Rightarrow a=\dfrac {4*10}{2\sqrt{3}}=\dfrac {20\sqrt{3}}{3} $
Area of hexagon $6
\left ( \dfrac {\sqrt{3}}{4}a^{2} \right )=6*\dfrac {\sqrt{3}}{4}\dfrac {20\sqrt{3}}{3}\dfrac {20\sqrt{3}}{3}=200\sqrt{3}$

With the help of a normal ruler and a compass only, which of the following line segment is possible to construct?

  1. $2.1\ cm$

  2. $4.2\ cm$

  3. $5.43\ cm$

  4. $3.3\ cm$


Correct Option: A,B,D
Explanation:

Least count of normal scale is $.1\ \ cm$ that is minimum length that can be measured using a normal scale is $.1\ \ cm$.

So the lengths that can be measured are
$2.1\ \ cm,4.2\ \ cm$ and $3.3\ \ cm$
To measure $5.43$ we need a scale whose least count is $.001$

Which of the following line segments can be drawn with the help of a ruler and compass ?

  1. $1.234\ cm$

  2. $2.15\ cm$

  3. $2.5\ cm$

  4. $3.04\ cm$


Correct Option: C
Explanation:

Least count of normal scale is $.1\ \ cm$ that is minimum length that can be measured using a normal scale is $.1\ \ cm$

So only $2.5 \ \ cm$ can be measured using a ruler and compass.
Hence option $C$ is correct.

With the help of a normal ruler, which of the following line segment is possible to construct?

  1. $3.1\ cm$

  2. $4.234\ cm$

  3. $7.2\ cm$

  4. $1\ cm $


Correct Option: A,C,D
Explanation:

Least count of normal scale is $.1\ \ cm$ that is minimum length that can be measured using a normal scale is $.1\ \ cm$

So the lengths that can be measures are
$3.1\ \ cm$$,7.2\ \ cm$ and $1cm\ \ $
Options $A,C$ and $D$ are correct.

The steps for constructing a line segment of given length are given in a jumbled order below:
1. Draw an arc on the line by keeping the pointed end of the compass on the point $A$. Mark the arc point as $B$.
2. Draw a line.
3. Extend the compass by keeping one end on the $0\ cm$ mark and other at the given length on the ruler.
4. Take a point $A$ anywhere on the line.

Which of the above steps comes last?

  1. $1$

  2. $2$

  3. $3$

  4. $4$


Correct Option: A
Explanation:

For constructing a line segment of given length steps are following:

Step 1 : Draw a line(2).
Step 2 :Take a point $A$ anywhere on the line(4).
Step 3 : Extend the compass by keeping one end on the $0 \ \ cm$ mark and other at given length on ruler(3).
Step 4 :  Draw an arc on the line by keeping the pointed end of the compass on the point $A$ .Mark the arc point as $B.$(1)
So $1.$ is the last step.
Option $A$ is correct.