You are Here: Home >< Maths

# C4 angles question aqa Watch

1. Hey I came across this question 2aii in Jan 2012 C4 and the mark scheme wants me to use pythagoras but how do I do that if the angle is obtuse by pythagoras I could calculate the actute angle which would be (1/sqrt(3)) but then hwo would I find the obtuse one from that which is -1/sqrt(3). I just did sin inverse 0.5 then found the obtuse angle 180-30 and then 'tan'ed that. But the mark scheme wangs use of pythagoras... My working and the mark scheme and the question have been attached. Thanks. Btw I got this exam tomorrow AQA . The question is 2a ii btw
Attached Images

2. It tells you in the question that angle B is obtuse, tan of an obtuse angle is negative which is why the answer is negative ie -1/sqrt(3)

Updated: June 13, 2012
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:
Today on TSR

### HELP!

Mum wants to come to Freshers

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