Construction of Angles

IMPORTANT

Construction of Angles: Overview

This topic covers concepts such as Constructing a 60 degrees Angle Using Ruler and Compasses, Constructing a 30 degrees Angle Using Ruler and Compasses, Constructing a 90 degrees Angle Using Ruler and Compasses, etc.

Important Questions on Construction of Angles

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IMPORTANT

Construct an angle of 22.5° using ruler and compass.

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Construct an angle which is half of 30° using ruler and compass.

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Construct an angle which is one-third of 45° using ruler and compass.

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Construct an angle of 15° using ruler and compass.

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Steps of construction:

1. Take any suitable radius and O as the centre, draw an arc which cuts a ray OA at point P.

2. With point P as centre and the same radius, mark an arc and name it as F. Again put your compass at F and with the same radius, draw an arc which intersects the initial arc at E.

3. Fix your compass at E, draw an arc with a convenient radius. Repeat the process by putting the compasses at F and let the two arcs intersect at B. Join OBBOA=90°.

4. Now, bisect the obtained angle between BO and OA. Mark it as OCCOA= _____°

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It is possible to construct the angle 135° using a compass and ruler.

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In the first square paper, the sides AB, AD are folded about the corner point A, in a way as shown in figure 2, so that the two folded parts overlaps each other perfectly.

When it is unfolded, the folds are marked as in figure 3.

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It is found that, DAE=EAF=FAB=30°

BAE=DAF=60°

Again if the side AD is folded about the point A such that AD coincides with AE, it is unfolded

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Then, DAG=_____°

EASY
IMPORTANT

To construct an angle of 60°, we need to draw first

HARD
IMPORTANT

Satish followed the steps given below

Step 1: Construct an angle of 90°.

Step 2: Bisect the 90° angle.

Step 3: Bisect one of the angles obtained in step 2.

Which step is not required to construct a 45° angle?

HARD
IMPORTANT

A circular piece of paper is divided into two equal parts.

Next, the semi-circular piece is again folded so that the folds are equal.

This folded paper is folded once again, as drawn in the figure. Once again it is folded.

Now, it is unfolded

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The angles formed are measured with a protractor.

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If the portion of 2212° is cut off, the measure of COD=120°.

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Step 1: Let us draw any line segment AB with scale pencil.

Step 2: Now, with centre A and with any radius, lets draw an arc with compass, so that it cuts the line segment AB at C.

Step 3: Next with centre C and with the same radius, lets draw an arc which cuts the previous arc at D.

Step 4: Now, the points D and A are joined and extended. The angle is formed DAB= _____°.

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IMPORTANT

Which of the following can be used to construct a 22.5° angle?

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IMPORTANT

If the angle which should be bisected to construct a 30° angle is x°, then find the value of x.

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Between 50° and 80°, only _____ ° can be drawn with the help of compass and ruler. 

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In the first square paper, the sides AB, AD are folded about the corner point A, in a way as shown in figure 2, so that the two folded parts overlaps each other perfectly.

When it is unfolded, we shall find the mark as in figure 3

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We find DAE=EAF=FAB=_____°

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Step 1: Draw a ray OA.

Step 2: With O as centre and any convenient radius draw an arc MN to cut OA at M.

Step 3: With M as centre and the same radius draw an arc to cut MN at P

Step 4: With P as centre and the same radius, draw an arc to cut MN at Q.

Step 5: Draw OQ and produce it to D. An angle is constructed.

If the measure of angle formed is x°, then write the value of x.

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IMPORTANT

Steps of construction:

1. Take any suitable radius and draw an arc which cuts ray OA at point P

2. With point P as centre and the same radius, mark an arc and name it as F. Again put your compasses at F and with the same radius, draw an arc which intersects the initial arc at E.

3. Fix your compasses at E, draw an arc with a convenient radius. Repeat the process by putting the compasses at F and let the two arcs intersect at B. Join OBBOA=90°.

4. Now, Bisect the obtained angle BO and OA. Mark it as OCCOA=45°.

5. Bisect 45° to get the required angle. The angles OC and OA are bisected and mark it as OD.

6. Hence, the required angle is DOA=_____°. (Express in decimal)

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IMPORTANT

A circular piece of paper is divided into two equal parts.

Next, the semi-circular piece is again folded so that the folds are equal.

This folded paper is folded once again, as drawn in the figure. Once again it is folded.

Now, it is unfolded

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The angles formed are measured with a protractor.

If the 45° portion is cut off, what is the measure of the angle in the other portion in degrees? 

MEDIUM
IMPORTANT

After constructing a 60° angle, if one of the arms of the angle is produced in the opposite direction, the angle formed is _____°

HARD
IMPORTANT

Which of the following angles can be constructed using ruler and compass?