We need the length of the sides.
AB=√(2-(-2))²+(4-1)²=√16+9=√25=5; BC=√4²+0=4; CA=√0+9=3. AB+BC+CA=5+4+3=12.
Since you are looking for the dollar per hour, can just set the equation up as dollar divided by hour (dollar/hour). You take how much was made ($173.70) and divide it by the hours worked (18 hours).
$173.70/18 = x (x representing how much he makes an hour).
$173.70/18 = $9.65.
Cameroon makes $9.65 an hour.
Slope = -4-5/8-2
Slope = -9/6