We need to note that this is an equation, in which we can solve for x.
We can use a calculator to find the tangent of 39 - we type 39 into the calculator then press the "TAN" button to find it's tangent. We find that to be around 0.81.
We now have the formula simplified down to . To solve for x, we want to isolate it on one side, so we can multiply both sides by 68 to get rid of the fraction.
On the left side, with 68 * (x/68), the 68's cancel out and leave us with x.
On the right side, with 68 * tan(39), we need to first solve for tan(39) and multiply it by 68.
Continuing the right side, tan(39), when using a calculator, is 0.8097840332 (make sure your calculator is in degree mode), and when this is multiplied by 68, this makes 55.06531425.