In this section, you’ll learn how to draw geometric figures in a coordinate system. That means you’ll be able to draw triangles, squares, and circles using coordinates and distances. A coordinate is a point in a coordinate system. It’s made up of one value from the -axis and one value from the -axis and looks like this: .
When you draw geometric figures in a coordinate system, you make crosses or dots at given coordinates, then draw lines between them. A typical assignment might be to have you find a final coordinate based on some given coordinates and a description of the figure.
Example 1
Given the points and , where do you have to put the final point to make a right triangle?
In this case there are two points that satisfy the demand for a right triangle. If you move along the -axis to , you can turn ° and move directly to the point . That means you can choose the point to make a right triangle. If you move along the -axis to , you can turn ° to the right and move straight to the point . That means you can choose the point to make a right triangle as well.
Example 2
Draw a circle with its center at and a radius of 3
In this case you first mark the center on the graph. Then, set up your draft compass with distance 3 between the legs. Put the point of the compass in the center and make a circle.
Example 3
You’re going to draw a square. You know that two of the corners are at and . Find the rest of the coordinates and draw the square.
There are multiple solutions to this problem, but you decide you will consider only the square with sides parallel to the - and -axes.
First, mark the points you already know: and . Then you find the distance between the values () and the distance between the values (). Choose one of the given points. Move 5 in the direction towards the other point. Mark a point. Next, move 5 in the direction from your chosen point towards the other point and mark that point. Those are the final points of the square.
Math Vault
Want to solve exercises about the coordinate system? Try Math Vault!