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# Graphical Triangle

What is the area of the triangle formed by the three lines whose equations are given below?$$y-x=6\qquad x-2y=3\qquad x+y=6$$

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.

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### Intersections

### Perpendicular Lines

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What is the area of the triangle formed by the three lines whose equations are given below?$$y-x=6\qquad x-2y=3\qquad x+y=6$$

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.

This problem is taken from the UKMT Mathematical Challenges.

You can find more short problems, arranged by curriculum topic, in our short problems collection.

Change one equation in this pair of simultaneous equations very slightly and there is a big change in the solution. Why?

Position the lines so that they are perpendicular to each other. What can you say about the equations of perpendicular lines?