I recently learned about circumcircles, incircles, circumradius, inradius, etc, but I don't really understand overall how to find them. Say I had a triangle with sides 10, 24, and 26. How would I calculate each of the above? An explanation would really help because I just don't understand how these are calculated. Thank you.

gwenspooner85 Jul 22, 2020

#1**+2 **

1) Find the perimeter **P = a + b + c**

2) Find semiperimeter **s = ( a + b + c ) / 2**

3) Find area **A = sqrt [ s( s-a )( s-b )( s-c )] ( Heron's formula )**

4) Calculate inradius **r = A / s**

5) Calculate circumradius **R = ( abc ) /4rs**

6) Inner angles **a ^{2} = b^{2} + c^{2} - 2bc * cos(A) ( The law of cosines ) **

I hope it covers everything you wanted to know.

Dragan Jul 22, 2020

#2**+1 **

Oh okay thank you, it helped me. For finding area of circumcircles and incircles, then you would just use the circumradius and inradius formulas to the find the radius, and continue on with the circle area formula correct?

gwenspooner85
Jul 22, 2020