How do I solve for an unknown variable from an equation using solver in Excel?

[Adam_s299020]

Im attempting to get excel to calculate the length of a side of a triangle using the formula =(a/SIN(A2)-34.4/SIN(B2)), where a is an unknown variable. Any help would be great. thanks.

[#2]

@Adam_s299020 

Firstly, why not rearrange the formula

(a/SIN(angleA)-34.4/SIN(angleB)

to read

 =34.4*SIN(angleA)/SIN(angleB)

Other options include calculating your formula for a whole range of values for 'a' and spotting the point at which it crosses zero or using goal seek to set 'a' to give zero. Solver is over-kill.