497 inches²
Step-by-step explanation:
Hi!
I have never done a problem like this in my life but I see exactly how it is meant to be solved. Lets try it out.
Let us first remind ourselves of the formulas we need for this.
Formula for a circle and the formula for a triangle.
Circle :
A = 
x r²
(or Area = pi x radius²) (Note that = 3.14)
Triangle :
A = b x h x 1/2
(or Area = base x height x 1/2)
Now lets see what the question wants from us and what we are given :
Gives us :
Diameter XY = 30 inches
YZ = 20 inches
XZ = 21 inches
And it wants the total area of the shaded regions to the nearest square inch. (Inches²)
Alright so first lets solve this triangle :
We need to do Base x Height x 1/2 :
Input your numbers given :
Base = 21in
Height = 20in
And lets multiply this out :
Base x Height x 1/2
21 x 20 x 1/2
21 x 20 gives us 420
Now we have :
420 x 1/2
Note that this is literally saying it wants half of 420. So we can actually just make it easier and do :
420/20
This gives us 210.
Great! Now we have the area of the triangle which is 210, this will be important later but for now lets move onto the circle.
Alright so we need radius to solve this but it really doesn't give us much about the circle.
But...
If you take a look at ∠YX you can see that it says 30in. This is actually the diameter of the circle and we can use this to find the radius of the circle.
The radius of a circle is 1/2 of the diameter.
And the diameter of a circle is 2 × the radius.
So in this case to find the radius we can actually take the 30inch diameter and divide it by 2 to find our radius.
30/2
=
15
Radius = 15inches!
Now lets look back to our wonderful circle formula.
A = x r²
or if we write it out :
Area = pi x radius²
So now lets plug in the radius we found and then solve to find the area of this circle.
Area = pi x 15²
(Don't forget the tiny 2 next to the 15!)
Now we can multiply this :
pi x 15²
=
706.858347058
Round to the nearest square inch :
707 inches²
(pi = )
So now what we have is the area of both shapes. It is smooth sailing from this point on. Let us recap :
Triangle Area = 210 inches²
Circle Area = 707 inches²
Now we have to find the area of the shaded area which is really simple subtraction.
The shaded area is the circle but the triangle is overlapping this shaded area so all we have to do is subtract the triangles area from the circles area so all that will be left is the shaded area of the circle.
So we do :
Circles area - Triangles area = Our answer
707 - 210 = 497
There we go!
Our answer is 497 inches²
This took a minute I am sorry about that but I hope this helps!
If you have any other questions please let me know.
