# Assignment 4 warm up

Hey, I've been struggling to work out the proof for assignment 4 question 1 part 2. I got the first part and the rest of the assignment already but I just can't work this one out. Thanks for any help

### Q1 (ii)

Start by drawing a diagram, and you should find that the lines $AP$ and $OB$ cross (or $BP$ and $OA$ depending on your diagram).

Add in a line $OP$. We then have triangles $AOP$ and $BOP$ which are both isosceles. We have:
$\angle{OAP}=\angle{OPA}=x \\ \angle{OBP}=\angle{OPB}=y$
From here you should be able to write $\angle {APB}$ and $\angle {AOB}$ in terms of $x$ and $y$.

### I also struggled until I went

I also struggled until I went back to my part i) diagram and redrew it with the same letters and x and y but with just P shifted around until O was outside the ABP triangle. Then it was a case of using the same method as in the first part.

Underground Mathematics: Selected worked STEP questions

STEP Question database

University of Cambridge Mathematics Faculty: What do we look for?

University of Cambridge Mathematics Faculty: Information about STEP

MEI: Worked solutions to STEP questions (external link)