Answer:
r = 5 cm
Step-by-step explanation:
A = πr²
78.53 = (3.14)r²
divide by 3.14
25 = r²
r = ±5
r = 5
11.7 units
sq root(2--4)^2+(-7-3)^2
sq root(6)^2 + (-10)^2
sq root (36)+(100)
sq root 136
equals 11.66 which rounds up to 11.7