consider a market where supply curve is horizontal at P = 10

Consider a market where supply curve is horizontal at P = 10 and the demand curve has a y intercepts at $34 and x intercept at 34units, and is defined by the relation P = 34 - Q (this is just a straight-line from 34 on the y axis to 34 on the x axis. Impose a tax of $2 per unit on the good so that the supply curve is now P = 12. How much is the Dead Weight Loss (DWL)? (hint: it's the area of a triangle)