Solid Hardwood, Engineered and Laminate Flooring - Need stairnose help

We put stairnose on a step that needed it on 3 sides & cut it at the 45* angle but the corners don't meet right. :wall:
How do I measure it to get the angles of the corners to meet? Do I measure it on the inside or the outside? :confused: Please tell me what to do!
This stuff is too expensive to experiment with!

Thank You!

Please help us! We don't know what the problem is to correct it. If we lay the stairnosing out on the floor the corners meet up ok. If we put it on the step the bottom meets up but the top corners gap a quater of an inch. off. We cut it at a 45* angle. Should the stairnosing be cut upside down? standing up on its side? We don't know what to do next. :wall:
We cut it laying flat with the wood side up, with a 45* angle. We are trying to picture frame the stairnosing on a step going down into the family room.

Thank You for your help!
Sarah

When doing box steps it is a good idea to make small scraficial 45º pieces of the nosing. Use them to make the side pieces where you want them, and then measure the long front nose, from long point to the long point on the 45º temporary side pieces. You can also get the length the side pieces need to be.

Measure and check 5 times!! Cut once!!! :)