The area formula of a circle is 
× π.
With that being said, we can solve both problems!
Starting with part A:
-The radius we know is 21cm. From there, we can substitute in our formula with the new value.
x π
From there, we can square our radius:
(21 x 21) x π
(441) x π
And finally, we can multiply by pi to get our answer.
(441) x π
1385.44236023
Which rounded to the nearest tenth is 1385.4. Therefore, the area of the porthole is 1385.4 centimetres.
The second part can be followed with the same process, hopefully you understand the concept enough to where you're comfortable solving problems like this on your own. Feel free to reach out if you have any further trouble!
<em>Hope this helped! :)</em>
This is a simple problem
First, take common sense and apply it here. The problem doesn't specifically tell you what the shape ACTUALLY is, but we can also apply what we know about geometry here, as well as what we know in general. Fish tanks most commonly come in 2 shapes: Square's and Rectangles. Fish tanks are what we call "3D" objects (meaning it's just not flat like a piece of paper", and the shapes are known as "Cubes and Rectangular Prisms".
Well, we know that squares/cubes have to have even sides. The problem states the tank is 5(l) by 2(w) by 2(h). This means it CAN'T be a cube, thus meaning it's a rectangular prism.
Now, to calculate volume, we have to know the formula. For this, the formula for volume is as follows: V=lwh
This means Volume=Length*Width*Height
So, do replace the words with what you know you already have. Let's make a list:
Length=5
Width=2
Height=2
V=lwh-----V=5*2*2
Now, work it out. 5*2=10*2=20, Left to right
Your answer here is V=20
~Hope this helps!
————————————-The answer is 3.78
<h2><em>y</em> = -3<em>x</em> + 1</h2><h2></h2><h3>y = mx + b</h3><h3>m = slope</h3><h3>b = y-intercept</h3>
The step in this problem is do 1/4 + 1/3= ?
and see what you get
