Area of a circle: A = πr² [pi times radius(r) squared]
So you just need to find the radius.
The radius is half of the diameter. Since they gave you the diameter, which is 14, just divide it by 2 or multiply by 1/2 to get the radius, which will be 7.
A = πr² Plug in 7 for r
A = π(7)² Find 7² [or 7 x 7 = 49]
A = 49π square units Your answer is 49π