Answer:
[tex]Diameter = 11.28[/tex]cm --- (a)
[tex]Diameter =22.58[/tex] cm --- (c)
Step-by-step explanation:
Only (a) & (c) are clear enough to be solved. Others are not properly presented.
Use the following explanations of (a) & (c) to answer others.
[tex]a.\ Area = 100cm^2[/tex]
Area is calculated as:
[tex]Area = \pi r^2[/tex]
Substitute 100 for Area
[tex]100 = \pi r^2[/tex]
Take π as 3.14. So, the expression become
[tex]100 = 3.14 r^2[/tex]
Divide both sides by 3.14
[tex]\frac{100}{3.14} = \frac{3.14 r^2}{3.14}[/tex]
[tex]\frac{100}{3.14} = r^2[/tex]
[tex]r^2 = \frac{100}{3.14}[/tex]
[tex]r^2 = 31.847133758[/tex]
Solve for r
[tex]r = \sqrt{31.847133758[/tex]
[tex]r = 5.64[/tex]
But diameter = 2 * radius
So:
[tex]Diameter = 2 * 5.64[/tex]
[tex]Diameter = 11.28[/tex]
[tex]a.\ Area = 400cm^2[/tex]
Area is calculated as:
[tex]Area = \pi r^2[/tex]
Substitute 400 for Area
[tex]400 = \pi r^2[/tex]
[tex]400 = 3.14 r^2[/tex]
Divide both sides by 3.14
[tex]\frac{400}{3.14} = \frac{3.14 r^2}{3.14}[/tex]
[tex]\frac{400}{3.14} = r^2[/tex]
[tex]r^2 = \frac{100}{3.14}[/tex]
[tex]r^2 = 127.388535032[/tex]
Solve for r
[tex]r = \sqrt{127.388535032[/tex]
[tex]r = 11.29[/tex]
But diameter = 2 * radius
So:
[tex]Diameter = 2 * 11.29[/tex]
[tex]Diameter =22,58[/tex]
