Formula for the area of a circle:
A = πr² [A = area r = radius]
The radius is 
(half) the diameter. Since the diameter = 10cm, the radius = 5cm.
You know:
r = 5cm Substitute/plug this into the equation
A = πr²
A = π(5)²
A = 25π -> A = 25(3.14)
A = 78.5cm²
Hello!
X = 11
to get this, divide both sides by 4
4X / 4 = X
44 / 4 = 11
X = 11
I hope this helps, and have a nice day!
The answer would be 173.55.
Explanation: it just is
Range is all y-values. This would be all real numbers or (-oo,oo)
