important Triangles Formulas

The power triangle explains the relationship between real, reactive and apparent power. The figure below displays the triangle:

Maths made Fun!, Share with your Friends and Teach Everyone the easy ways of Solving, Right-Angled Triangle Formula. 

I - We know the 3 sides (a, b, c)

P=(a+b+c)/2 TAN(A/2)=RACINE((p-b)*(p-c)/p*(p-a))
a/SIN(A)=b/SIN(B)=c/SIN©=2R
S=RACINE(p*(p-a)*(p-b)*(p-c))

II - We know 1 angle and 2 Adjacent sides (b, c, A)

a^2=B^2+C^2-2*b*c*COSA
TAN(B-C)/2=(b-c)/(b+c)*COT(A/2)
S=1/2a*b*SIN(C )=abc/4R=rP
A+B+C=200

III -2 angle and the common side (B, C, a)

A=200-B-C
S=1/2*a^2*SIN(B)*SIN(C)/SIN(B+C)

IV -1 angle and 2 sides (A, a, c)

a/SINA=b/SINB=c/SINC
C=200-ASIN(c*SINA/a)
b=aSINB/SIN(B+C)
S=1/2*c^2*(SINA*SINB)/SIN(A+B)