You are Here: Home >< Maths

# Straight lines and areas watch

1. So as you can see I've got as far as working the equation of the line that's perpendicular but how I do now work out the area? I guessed it would be 0.5 multiplied by something since it's a triangle- I don't know please help
2. (Original post by Lucofthewoods)
So as you can see I've got as far as working the equation of the line that's perpendicular but how I do now work out the area? I guessed it would be 0.5 multiplied by something since it's a triangle- I don't know please help

OK, you've got the line y=-2x+9 ...(1), and you want the area of the triangle OAB.

So, you need to know where A and B are. In your answer you've labelled the two given points at A and B, but that's not the case.

A is the point where your new line meets the x axis. So, sub y=0 into your equation (1) and solve for x, and this will be the length of OA.

Can you now find B and complete it?

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: November 14, 2016
The home of Results and Clearing

### 3,928

people online now

### 1,567,000

students helped last year
Today on TSR

### IT'S TODAY!

A-level results chat here

### University open days

1. Bournemouth University
Fri, 17 Aug '18
2. University of Bolton
Fri, 17 Aug '18
3. Bishop Grosseteste University
Fri, 17 Aug '18
Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams