Right Angles
We shall often need to draw right angles so let us learn how to draw
a right angle accurately using a ruler and a pair of compasses. If the
angle between two lines is 90 degrees we say that the two lines are perpendicular
to each other. When you are ready with a ruler and a pair of compasses,
click on the start button in the applet.
Activity
Below is the plan of a park ABCD with straight edges. It is divided into
regions as shown. The boundaries AE, EF, FD, DJ, JC are each 100 yards while AB is 50 yards.
a) Draw a scale diagram to discover the lengths of the other boundaries.
b) What is the area of each of the regions?
c) What is the perimeter of each of the regions?
d) The boundaries of the park are destroyed in a storm. However two trees, one at I and one at J
remain. Using only the information originally given can you reconstruct all the boundaries? [Hint;
Start with the boundary from I to J and draw perpendicular lines at either end. ]
