Thursday, 8 September 2016

geometry - Easier way of finding radius of circle inscribed in a scalene triangle given 2 sides and the included angle

I have a scalene triangle with two sides given and the included angle. I am solving for the radius of the inscribed circle. See the image below.
enter image description here



I know that I can use the law of Cosines to find the length of the missing side
c2=a2+b22abcosC




Then I could use area of a triangle formula



K=12absinC



Finally I could find and insert the perimeter and area into the formula below to solve for r.



r=2Ap



My equation for r would be:




r=absinCa+b+a2+b22abcosC



Using the given data this would give me:



r=119202sin(43)119+202+1192+20222119202cos(43)=35.5



Is there a simpler way to do this?

No comments:

Post a Comment

real analysis - How to find limhrightarrow0fracsin(ha)h

How to find limh0sin(ha)h without lhopital rule? I know when I use lhopital I easy get $$ \lim_{h\rightarrow 0}...