The angles diagonally opposite each other are congruent while those adjacent to each other add up to 180 degrees. You can get eight congruent angles with a transversal if the two lines are parallel, because each angle would be 90.
1. 4.374
2. 52.64
3. 840.5
11x = -7y
this is the answer because you combine the x together
Surface area is the areas of all the faces added up. Volume is how much a 3D figure can hold.