Using A Protractor

1. Using A Protractor Click on the right arrow to advance The box to the left of the right arrow will end the show

2. The outside scale is used when the angle opens to the left . It starts on the left with 0° and ends on the right at 180°. Between each group of ten you will see lines indicating 1 degree each. Every five degrees the line is a little larger. To use the outside scale you need to place the center point at the vertex of the angle and the 0°line on the left leg of the angle. You then can read the measure of the angle by reading the point where the right leg of the angle crosses the protractor. The protractor above uses the inside measure because the angle opens to the right. You will notice that the inside is marked off in 10° intervals. When you place the center mark at the vertex of the angle and the 0°line on the right leg you then can read the angle by checking the left leg. You first read the group of ten on the inner scale then slide out to count the individual degrees on the outer scale until you reach the left leg of angle. Above you see that the angle measures 60°. The protractor below has two scales on it. An inside scale and an out side scale. Click on the right arrow on the bottom to advance Click on the right arrow to advance The box to the left of the right arrow will end the show

3. Here is another angle Click on the right arrow at the bottom to create the angle D A C Notice that the angle opens to the right. The center of the protractor is on the vertex of the angle and the base leg is on the zero line. We will use the inner scale counting up to 20° then we slide out to the outside to count the individual degrees. In doing this you see that we have 6 lines on the outer scale and if we add these to the 20° you end up with a 26° angle. Click on the right arrow to advance The box to the left of the right arrow will end the show

4. Create the angle by clicking on the right arrow at the bottom H F G Notice that the angle opens to the right. The center of the protractor is on the vertex of the angle and the base leg is on the zero line. We will use the inner scale counting up to 50° then we slide out to the outside to count the individual degrees. In doing this you see that we have 6 lines on the outer scale and if we add these to the 50° you end up with a 56° angle. Click on the right arrow to advance The box to the left of the right arrow will end the show

5. Create the angle by clicking on the right arrow at the bottom U S T Notice that the angle opens to the Left. The center of the protractor is on the vertex of the angle and the base leg is on the zero line. We will use the outer scale counting up to 40° then count the individual degrees. In doing this you see that we have 4 lines past the 40° and if we add these to the 40° you end up with a 44° angle. Click on the right arrow to advance The box to the left of the right arrow will end the show

6. Create the angle by clicking on the right arrow at the bottom T R Q Notice that the angle opens to the Left. The center of the protractor is on the vertex of the angle and the base leg is on the zero line. You see that the other line is past 90° so our angle will have a measure greater thasn 90°.We will use the outer scale counting up to 120° then count the individual degrees. In doing this you see that we have 4 lines past the 120° and if we add these to the 120° you end up with a 124° angle. Click on the right arrow to restart the article The box to the left of the right arrow will end the show