# I need help constructing a triangle!!!!

• Oct 11th 2008, 09:05 AM
joesmith13610
I need help constructing a triangle!!!!
construct triangle from side a, angle (alpha), and radius.
(but, keep only a part of the condition, drop the other part: disregard the radius, but keep side a and angle (alpha), what is the locus of the center of the inscribed circle?)

thanks everyone
• Oct 13th 2008, 08:33 PM
earboth
Quote:

Originally Posted by joesmith13610
construct triangle from side a, angle (alpha), and radius.
(but, keep only a part of the condition, drop the other part: disregard the radius, but keep side a and angle (alpha), what is the locus of the center of the inscribed circle?)

thanks everyone

I assume that the angle $\alpha$ is opposite the side a.

If so:

1. Draw the side a which has the endpoints B and C.

2. Draw the perpendicular bisector of a.

3. Draw in B (or C) the angle $90^\circ - \alpha$ with a as one leg.

4. The other leg of the angle cuts the perpendicular bisector in M, the midpoint of the circumscribed circle.

5. Have a look here: Central Angle Theorem - Math Open Reference
• Oct 14th 2008, 08:20 AM
joesmith13610
thank you.

I'll give this a try.