If it's not what You are looking for type in the equation solver your own equation and let us solve it.
d in (-oo:+oo)
30.84 = (3.14*d)/2 // - (3.14*d)/2
30.84-((3.14*d)/2) = 0
30.84-1.57*d = 0
30.84-1.57*d = 0 // - 30.84
-1.57*d = -30.84 // : -1.57
d = -30.84/(-1.57)
d = 19.6433121
d = 19.6433121
| 5^4/5 | | 50/n=5/3 | | 2a-8b=13 | | v-5+v=7 | | 3(x-2)+x=2(x+1) | | x^2-22+85=0 | | (4x-28)/3=2x | | 50/n=20/12 | | 2x^2-22x+85=0 | | 3/2=b/8 | | 15/g=12/8 | | 4.5+1.5k=8-3k | | 0=9x-3x^2 | | Log=log^2 | | (25x-10)=(7y-4) | | Log^5*x+log^5*(x+1)=log^5*20 | | (2x+24)=142 | | 102+100+92+5x+16=360 | | (Log^5*x)+log^5*(x+1)=log^5*20 | | 18=22n | | 41.12=3.14*2r/2 | | Cos(54)=x/30 | | 4-3/y-3=-3/y-2 | | a/24-21=7 | | 2a-7=7 | | x=9+13 | | 15/D=.095x | | 3x-5+5(x-3)=12 | | 6a-7=2(2a-13) | | -7b-5=-3(b+2) | | 41.12=3.14d/2 | | 2x=6y+y^2+11 |