#USING A PROTRACTOR HOW TO#

The angle protractor tool and 360° protractor give more precise measurements.

We can also use a 360° protractor to draw a reflex angle.

It is commonly used in the field of architecture, mechanical drawings, and meteorology. Therefore, ∠CAB = 40°.Ī 360° protractor is circular in shape and has readings up to 360° in the clockwise direction.

Step 5: Now using a scale, join A and C.

Step 4: In the inner readings, look for 40º and mark it as point C.

Step 3: Since the angle is drawn on the right-hand side of the vertex we will see the inner readings.

Step 2: Align the baseline of the protractor on AB such that the center of the protractor is placed on point A.

#USING A PROTRACTOR HOW TO#

Let us see how to draw an angle of 40º using a protractor. In order to draw angles using a protractor, we use the following steps. This can be verified by the values, that is, 150º + 30º = 180º. It should be noted that ∠AOC + ∠BOC form a straight line and hence add up to 180. Step 2: Check the reading where the ray OC is formed.Since we need to measure ∠AOC, which is formed on the left-hand side of the center, we will use the outer readings which go clockwise. Step 1: Place the baseline of the protractor on line AO such that the centre of the protractor is placed on vertex O.Now, let us find the measure of ∠AOC using the following steps. Step 3: Now, identify the reading on the protractor where ray C is extending.Step 2: Since the angle is formed on the right-hand side of the center, we will use the inner readings which go anti-clockwise.Step 1: In order to measure the angle ∠BOC, align the baseline of the protractor with the line AB such that the center circle of the protractor is at the vertex O.

In this case, ∠BOC = 120°.įor measuring angles with a protractor, let us use the following steps and relate to the figure given below.

Step 4: If the angle to be measured is formed on the right-hand side from the center of the protractor, we need to use the inner readings of the protractor.

If the angle to be measured is formed on the left-hand side from the center of the protractor, we need to use the outer reading of the protractor.

Step 3: Decide which readings are to be followed.

Step 2: Place the baseline of the protractor on the ray which is the base of the angle.

Step 1: We first need to pIace the center (hole) of the protractor on the vertex O.

Observe the following figure to know how to read a protractor and relate to the steps given below. Each inner reading and outer reading supplements each other, i.e., they add up to 180°. How to Read a Protractor?Ī protractor can be read using its inner readings or its outer readings depending on the angle that is formed. It has two readings - the outer reading and the inner reading that help to measure a given angle. A protractor is an instrument which is very easy to use.

Using a protractor