-1275*2340/(-1475)

N[%]

Solve[-1475/2340==-1275/x,x]

N[%]

B==Sqrt[h*w]/60

Solve[B==Sqrt[h*w]/60,h]

Solve[B==((Sqrt[h*w])/60),h]

B=Sqrt[h*w]/60

Sqrt[80]

B/.{w-> 80}

B/.{w-> 80,h->200.0}

B2[h_,w_]=Sqrt[h*w]/60

B2[200.0,80]

B2[h,80.0]

Plot[B2[h,80.0],{h,0,250}]

Plot[{B2[h,80.0],B2[h,60.0],B2[h,100.0]},{h,0,250}]