You can use a protractor to measure and draw angles. To measure angles with a protractor, first place the center point along the bottom edge of the protractor over the vertex of the angle you're measuring. Line up the bottom edge of the protractor with one leg of the angle.

is that **protractor is one who, or that which, protracts, or causes protraction** while ruler is a (usually rigid), flat, rectangular measuring or drawing device with graduations in units of measurement; a rule; a straightedge with markings; a measure.

The most common protractor is a semicircle with 180 degrees marked on it. To draw or measure a full circle, you must flip the protractor over. **A compass, on the other hand, can draw circles of different diameters depending on the placement of the center point and the length of angle between the center point and pencil.**

Measuring Angles

The two scales **make it easy for us to measure angles facing different ways**. To measure the size of angle ABC, place the protractor over the angle so that the centre of the protractor is directly over the angle's vertex, B; and the base line of the protractor is along the arm, BA, of the angle.

Cleaning. If the tool does become dirty after being used, simply **use a soft, moist cloth to clean it**. Do not allow materials to enter or build up around the O-ring as this could affect the rotational movement of the arms.

protractor (n.)

1610s, "one who lengthens (an action)," **Modern Latin agent noun from Latin protrahere "to draw forward"** (see protraction). Medieval Latin protractor meant "one who calls or drags another into court." The surveying sense of "instrument for measuring and drawing angles on paper" is recorded from 1650s.

A ruler is for measuring segments and drawing segments of a specific length. **A protractor can be used to measure angles as well as draw angles of a specific measure**.

A protractor is a simple measuring instrument that is used to measure angles. A common protractor is **in the shape of a semicircle with an inner scale and an outer scale and with markings from 0° to 180° on it**.

**Using a paper square fold the square exactly in half lengthwise and along each diagonal.**

- A piece of origami paper makes a good square to use.
- You can cut a perfect square by folding the top edge of a piece of printer paper to align with a side edge.
- Use the fully opened square to trace a 90º angle on your protractor.

The half-circle protractor is commonly used to measure angles (Figure 9). The inner number scale rises from **0 to 180, from right to left**, and the outer scale goes from 0 to 180, left to right. Learners commonly make mistakes because they are not using the correct scale when measuring the angle between two lines.

plane angles

You can use a protractor to measure and draw angles. To measure angles with a protractor, first place the center point along the bottom edge of the protractor over the vertex of the angle you're measuring. Line up the bottom edge of the protractor with one leg of the angle.

**The compass is used to draw circles and arcs, while the protractor helps you measure and make plane angles**. Signing up for a geometry class means you'll likely need two essential supplies: a compass and a protractor.

**If the angle opens to the right side of the protractor, use the inner scale.** **If the angle opens to the left of the protractor, use the outer scale**.

**A protractor** is one of the most common tools to measure angles.

Dated : 08-Jul-2022

Category : Education