Okay so for these two questions you need to know the formula of the circumference and area of circle before attempting the question.

Circumference of Circle = 2*pi*r (where 'r' is the radius of the circle)

Area of Circle = pi*r^2 (pr*r*r, where 'r' again is the radius of the circle).

So with regards to your question now:

Circumference = 2*pi*4 = 8*pi = 25.1327 = 25.1m (rounded to the nearest tenth) (Don't forget the unit of measure 'meters' in this case)

Area = pi*(4)^2 = 16*pi = 50.2655 = 50.3 m^2 (rounded to the nearest tenth)