Answer:
a) r = 7in
b) d = 30cm
Step-by-step explanation:
A = [tex]\pi[/tex]*[tex]r^{2}[/tex]
A = area of a circle
r = radius
a)A = [tex]\pi[/tex]*[tex]r^{2}[/tex]
we divide by [tex]\pi[/tex] both sides of the equations
[tex]\frac{A}{\pi }[/tex] =[tex]r^{2}[/tex]
lets apply square root to both sides of equality sign:
[tex]\sqrt{r^{2}} =\sqrt{\frac{A}{\pi}}[/tex]
so we have:
[tex]r=\sqrt{\frac{A}{\pi}}[/tex]
[tex]r=\sqrt{\frac{49\pi}{\pi}}[/tex]
r=7 in
b)d= diameter
r=radius
d=2*r
[tex]r=\sqrt{\frac{A}{\pi}}[/tex]
[tex]r=\sqrt{\frac{225\pi}{\pi}}[/tex]
r=15 cm
so we have:
d=2*15cm= 30cm
