# Thread: Calculate side from angles and some other sides in triangle

1. ## Calculate side from angles and some other sides in triangle

Hello,

I would like the forumla for calculating the length of B.

What is known is the length of A (the entire length of that side), A2, D, D2 the angle of r and r2 (90 degrees).

What is the formula for calculating the length of B?

Regards,
Niklas

2. similar triangles
A2/A = D/B
A2 x B = A x D
B = (Ax D )/A2

3. Gee, so simple. Hope it's a good excuse that it was over 12 years ago I studied this...

Thank's a lot!