Hi. I have a disability. And I work in a group home with people with disability. I’m trying to do things with them. Like a bird house and other projects.

So I have a question on Angle

How do you make them meet on the corner.
Like if my frame is 8 by 8 on straight line how do you turn 8 by 8 into corner of 45 degree ?
7.50 by 7.50?
Like if you see a box. The box is 8 by 8. How do you make them meet on 45 degree angle
Like the corner of the door when you walk in. They put trims around the door and they are 45 angle on the corner. I know how to cut them but how do you get the measurement right ? So if I do a birdhouse and it ie 6 by 5. What is the measurement on the trims for that ? Because on the bottom of the birdhouse. I went to put trims. I want them to he on a 45 degree angle on the bottom of every corner. So how do i get 6 by 5 and turn them into 45 degree angle ?