nazn wrote:
CB wrote:
If the walls are straight, it's easy to go out at 90 degrees
using a 345 triangle.

I just assumed the house walls would be straight and hence my plan to
build at 90 degrees, what is a 345 triangle?, I expect this is 3 pieces
of timber I would lash up to make the triangle to put against the house
walls??

You could do that... mark three pieces of timber with
lengths of 3, 4, and 5 units. Nail together. Use this
triangle as a set-square. You could probably use a
large home-made pair of compasses to do the same job,
just as we did in early trig. at school.

You are posting from Google Groups. There's some way
of including context in your posts, which would be
quite helpful.