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.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.
This is the issued protractor, the metres scale romers are on the left side, these are the romers that you should use.Įnsure the map is on a flat surface, align the base line with the vertical lines on the map, the 0 should be in line with Grid North. Place the protractor over the map and align the northings and eastings with the zero lines and romer grids.Use a line of fine cord from the centre point when plotting bearings, a plumb line.Tape up the yard scale romer to avoid mistakes.Always check the scale of the map and scale of the romer when plotting grids.The protractor should always be used when plotting grids and bearings.The British Military only use mils in navigation.