Sin A = opp/hyp = 4/5
Cos A = adj/hyp = 3/5
Tan A = opp/adj = 4/3
Cos 27 = 0.8910065... --> 0.89
You can just plug that into your graphing calculator, just make sure the degree mode is on.
The measure of angle 1 and 2 should add up to 180°, because it forms a straight line. The same goes for the sum of angle 3 and 4.
Since we are given the measure of angle 2, we can find the measure of angle 1 by subtracting 143° from 180°.
180°-143° = 37°
We know that the intersecting lines form 2 sets of vertical angles, which are congruent. This means that the angles opposite from each other have the same measure. Therefore, both angle 2 & 4 have a measure of 143°, while angle 1 & 3 have a measure of 37°.
3.24 + 5.70 + 6.17 = 15.11
20.00 - 15.11 = 5.11
He got 5.11$ of change back.