Answer:
18cm
Step-by-step explanation:
We have the length of the rectangle but we need to find the width which we'll call w. Area is a, l is length.
a = l * w
20 = 5 * w
divide both sides by 5 to cancel the multiplication by 5 on the right side
4 = w
The rectangle is going to have two sides that are the length of l, and two sides that are the the length of w. We're looking for the perimiter p.
p = 2l + 2w
p = (2 * 5) + (2 * 4)
p = 18
It equals 2(x+1) blah blah blah
I is the right one because it is a half and they both look the same
Answer:
Option (4).
Step-by-step explanation:
Outer diameter of the hollow metallic ball = 10 centimeters
Outer radius of this ball =
= 5 cm
Volume of the outer ball
= 
= 
Inner radius of the hollow metallic ball = (5 - 1) = 4 cm
Volume of the inner hollow ball
= 
Volume of the metal used in the metallic ball = 
= 
= ![\frac{4}{3}\pi [(5)^3-(4)^3]](https://tex.z-dn.net/?f=%5Cfrac%7B4%7D%7B3%7D%5Cpi%20%5B%285%29%5E3-%284%29%5E3%5D)
Therefore, expression given in option (4) will be used to measure the volume of the hollow metallic ball.