If you have a graphing calculator then it is easy to graph
A = (a+b)/2
2*A = 2*(a+b)/2 ... multiply both sides by 2
2A = a+b
2A-a = a+b-a ... subtract 'a' from both sides to isolate b
2A-a = b
b = 2A-a
Answer: b = 2A-a
If the radius is 25, the diameter is 50.
Use C = (3.14)(50)
C = 157
No need round off to the nearest tenth.
The expression that gives an angle that is coterminal with 300 is 300-720. Two angles are said to be coterminal if when they are drawn in a standard position, their terminal sides are on the same location. The expression gives an angle of 420 where when it is drawn the terminal sides are on the same location with the 300.
Someone asked the same question here before, check it out