Tag: open and closed figures

Questions Related to open and closed figures

A man goes $15m$ due west and then $8m$ due north. How far is he from the straight point?

  1. $17m$

  2. $19m$

  3. $18m$

  4. $20m$


Correct Option: A
Explanation:

The least distance between the start and the end point can be calculated by the square sum root of the two distances travelled since north and west directions are perpendicular to each. hence, 
Least distance = $\sqrt{(15^2 + 8^2)}$
Least distance = 17 m

Which of the following alphabet represents a closed curve?

  1. U

  2. R

  3. C

  4. O


Correct Option: D
Explanation:

In simple closed curves, the shapes are closed by line-segments or by a curved line.

Triangle, quadrilateral, circle, etc., are examples of closed curves.

Instruments used to draw circle

  1. scale and setsquare

  2. scale and protractor

  3. scale and compass

  4. scale


Correct Option: C
Explanation:

In order to draw a circle, first we need a compass and we need to take the required radius length with the help of a scale.

So, the required tools are scale and compass.

When you draw without lifting your pencil or pen on a paper you get?

  1. Plane curve

  2. Plane shadow

  3. 3-dimension

  4. Line


Correct Option: A
Explanation:

When we join no. of points without lifting our pen we make a shape which not necessarily should be straight or curve. We get a plane curve.
Therefore, A is the correct answer.

The curve that crosses .................. is not a simple closed curve.

  1. other

  2. itself

  3. curves

  4. All of the above


Correct Option: B
Explanation:

When the curve crosses itself it has end points. While a simple closed curve does not have any end points.
Therefore, B is the correct answer.

A curve which has 2 end points is called an .....................

  1. closed curve

  2. simple curve

  3. open curve

  4. None of the above


Correct Option: C
Explanation:

An open curve is a curve whose end points do not join. In other words it has 2 end points.
Therefore, C is the correct answer.

Which of these is an example of an open curve?

  1. Circle

  2. Triangle

  3. A line segment

  4. Pentagon


Correct Option: C
Explanation:

As the line segment has end points, it is an open curve.
Therefore, C is the correct answer.

A closed curve has no ....................

  1. joints

  2. starting points

  3. end points

  4. All of the above


Correct Option: B,C
Explanation:

The beginning point and the ending point in a closed curve is the same. There are no end points and starting points. Eg. Circle.
Therefore, B and C is the correct answer.

State whether the following statements are true of false
Circles with same radii are equal

  1. True

  2. False


Correct Option: A
Explanation:

The statement is true.

Dimension of circle is defined by its radius so if they have same radius the circles are equal

A circle divides a plane in which it lies including itself in :

  1. 2 parts

  2. 3 parts

  3. 4 parts

  4. 5 parts


Correct Option: B
Explanation:

A circle drawn on a plane divides into 3 parts:

  • Exterior- Any point outside the boundary of circle.
  • Interior- Any point inside the boundary of circle.
  • Boundary- Any point on the circle.