Coordinate Codes

Part 2 - Letters and Lines

1. The letter A lies on the line 𝑥 = 1.

• Look at the coordinate axes above and try to explain why this is true.

• Which other letter lies on the line 𝑥 = 1?

• Which letters lie on the line 𝑥 = 5?

• Which letters lie on the line 𝑥 = −8?

2. The letter W lies on the line 𝑦 = 8.

• Which letters lie on the line 𝑦 = 5?

• Which letters lie on the line 𝑦 = −5?

3. Write down the equation of the line that passes through the letters:

• L and Z.

• O and S

• I and N

• Y and Q

• G and T

4. Only one letter lies on the line 𝑦 = 𝑥. Which letter is this? Explain how you know.

5. Only one letter lies on the line 𝑥 + 𝑦 = 10. Which letter is this? Explain how you know.

6. Which letters lie on these lines? Each time explain how you know.

• 𝑥 + 𝑦 = 6

• 𝑥 + 𝑦 = 11

• 𝑦 − 𝑥 = 5

• 𝑥 − 𝑦 = 4

• 𝑦 − 𝑥 = 7

7. Three letters lie on the line 𝑦 = 𝑥 + 4. Which letters are they? Explain why.

8. Write down as many different equations of lines as you can that the point R

lies on?

Part 3 - Sloping Lines

1. Draw a set of axes.

   • The 𝑥 axes should go from 0 to 8 and the 𝑦 axes from 0 to 8.

2. Use the clues below to plot the letters in the correct place.

   • Point A lies on the line 𝑥 = 3 and 𝑦 = 2

   • Point B lies on the line 𝑥 = 1 and 𝑦 = 5

   • Point C has an 𝑥 coordinate of 1 and lies on the line 𝑥 + 𝑦 = 3

   • Point D has a 𝑦 coordinate of 4 and lies on the line 𝑥 + 𝑦 = 9

   • Point E lies on the line 𝑦 = 3 and 𝑦 − 𝑥 = 1

   • Point F lies on the line 𝑥 = 6 and 𝑦 = 𝑥

   • Point G lies on the line 𝑦 = 𝑥 and 𝑥 + 𝑦 =8

   • Point H lies on the line 𝑦 − 𝑥 = 2 and 𝑥 + 𝑦 = 6

3. Draw yourself a set of axes and mark some letters at different points on the axes.

4. Make up some clues so that someone else could try to work out where your points were if you rubbed them all out.

   • Pass your clues to you friends and see if they can solve them correctly.

If you have understood today's lesson, you should be able to do the following questions: