# Homework Help: Geometry problem help

1. Nov 26, 2007

### lolerlol

1. The problem statement, all variables and given/known data

Let AD be and altitude of triangle ABC where angle A is 90 degrees.

Squares BCX1X2, CAY1Y2 and ABZ1Z2 are drawn outwards from the sides.

Let AX1 meet BY2 in U and AAX2 meet CZ1 in V

Prove that each of the quadrilaterals ABDU, ACDV and BX1UV is cyclic

2. Relevant equations

3. The attempt at a solution

I'm not sure where to start, but I've been given a clue

If angle BUA = angle BDA, the ABDU is cyclic
Let the point where BY2 meets AC be P
Consider triangles AUP and Y2CP

2. Dec 13, 2007

### Ouabache

Welcome to physics forums!! As you may have noticed, this is a great place to discuss ideas and problems you may encounter, in math and science.

On your problem, I would start by re-reading this post. There are many knowledgable people here, who are willing to steer you towards a successful solution. But first, you need to try to do some work on your problem and show us.

I recommend drawing the problem out as you've described it. A large drawing is useful, since you should see separation of the lines you draw, more clearly. I would also recommend using a pencil with a good eraser and a straight edge for this part.
Next, post what you have drawn as an image.

Can you tell us what a cyclic quadrilateral is?
(hint: if you cannot find it in your text, look it up on the web).