Line below will be one arm of the angles you are going to construct. Step 4: Use a ruler to line up the two _ and draw a straight line that passes exactly through them.Ĭonstruct the angles using the line below. Step 3: Make a small, clear mark at the _ Step 2: Place the protractor with its _ on the line and its origin exactly on top of the _ Sometimes you must use a specific point on the line.) Step 1: Choose a point anywhere on the line. Use your understanding of a protractor to draw a 90° angle. You must mark this point clearly and neatly with a small dot. Your first challenge is to construct a line at exactly right angles to the oneīelow. You need your protractor, a sharp pencil and a straight ruler. Work together with a partner on this activity. Using a protractor to construct angles Constructing angles to a given line Try to do some further investigation and show your teacher what you Protractor cannot measure reflex angles like angles 7 and 8. Some angles can be measured directly, others not. You can extend theĪrms if you need to it doesn't matter if they go across text or anotherįollowing figure. Measure the angles and complete the table on the next page. Measure an angle? Practise measuring with a protractor Do you agree? Do you see that there are two ways to Then the correct position looks like this:Ībove is 37°. You can also place the protractor on the angle using the other arm. The other angle arm passes under the degree scale. You choose the correct scale byįinding the one that starts with 0° on the angle arm. Moves⦠start again! You are now ready to make aĭegree scale and an anticlockwise degree scale. Be careful to line the ruler up with the arm.Ĭorrect place keep a finger on the protractor to stop it from moving. If they are too short, use a sharp pencil and a ruler to make them longer. The angle arms must be a little longer than the distance from the origin of the protractor to its edge. How to use a protractor to measure an angle The angle at the origin of the protractor? In a group of three or four, use your protractor to measure the angles that you If you didn't do that activity, then go back now and follow the instructions in question 5. You need the four folded angles from the previous activity. Size of the protractor makes no difference to Protractors can be big or small but they all Look at the picture of a typical protractor with its important parts labelled. We have a special instrument for measuring angles. The table by filling in the size of each angle described. Thousands of years ago that a revolution should be divided into 360 equal parts. No one today is completely sure why, but our ancestors decided many The units we use for measuring angles are veryĪncient. You know that we use metres, centimetres, kilometres, millimetres, etc. We need units and measuring instruments in many situations. Soccer field without being able to measure accurately in metres? Imagine if we didn't have units for measuring length.Ĭlothes to the right size without a tape measure? How could an architect designĪ safe and beautiful house without a ruler? How could we lay out a professional The arms and the vertices are in each of your examples. Situations in everyday life where objects are turned through angles? Say what Is the angle at 3 o' clock the same as the angleīook you can make different angles. Angle between the hands at 8 o' clock is the same size as the angle at 4Ĭompare the angle at 2 o' clock with the angleĪt 4 o' clock.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |