It will take 5 full rotations for Elena's car to travel ten yards
explanation: 10 yards=30 feet, and there are 12 inches in one foot. multiply 30 by 12. once you do that, you get 360. next, divide 360 by the 72 inches in each full rotation. 360/72=5. so the answer is 5 full rotations
Your statement that angle C and angle D adding to 180 degrees isn't always true. What is always true is that angle A and angle C add to 180 degrees.
Rule: The opposite angles of an inscribed quadrilateral are supplementary (add to 180 degrees)
So,
(angle A) + (angle C) = 180
(x+2) + (x-2) = 180
x+2+x-2 = 180
2x = 180
2x/2 = 180/2
x = 90
Once you know x, you can find the angles
measure of angle A = x+2
measure of angle A = 90+2
measure of angle A = 92 degrees
measure of angle C = x-2
measure of angle C = 90-2
measure of angle C = 88 degrees
Note how A+C = 92+88 = 180
measure of angle D = x-10
measure of angle D = 90-10
measure of angle D = 80 degrees
measure of angle B = 360-A-C-D ... see note below
measure of angle B = 360-92-88-80
measure of angle B = 100 degrees
Note: for any quadrilateral, the four angles add to 360 degrees. So A+B+C+D = 360. We can solve for B to get B = 360-A-C-D
3sqrt3
Side lengths of a 30-60-90 triangle are x xsqrt3 and 2x