Answer:
- Exact Area = 210.25pi - 210
- Approximate Area = 450.185
The units for the area are in square inches or in^2. The approximate value shown above is when using pi = 3.14
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Explanation:
Use the pythagorean theorem to find the length of the hypotenuse
a^2 + b^2 = c^2
20^2 + 21^2 = c^2
400 + 441 = c^2
c^2 = 841
c = sqrt(841)
c = 29
The hypotenuse is 29 inches long. This is the diameter of the circle. Half of that is the radius at r = d/2 = 29/2 = 14.5 inches.
The area of the circle is...
A = pi*r^2
A = pi*(14.5)^2
A = pi*210.25
A = 210.25pi
Which is exact in terms of pi
We'll subtract off the triangular region as this isn't shaded in. The area of the triangle is base*height/2 = 20*21/2 = 420/2 = 210 square inches.
So the shaded region is therefore 210.25pi - 210 square inches
This approximates to 210.25*3.14 - 210 = 450.185 when using the approximation pi = 3.14; use more decimal digits of pi to get a more accurate value.
Answer: 
Step-by-step explanation:
Given the following expression shown in the picture:

You need to use a process called "Ratinalization".
By definition, using Rationalization you can rewrite the expression in its simplest form so there is not Radicals in its denominator.
Then, in order to simplify the expression, you can follow the following steps:
<em>Step 1</em>. You need to multiply the numerator and the denominator of the fraction by
, which is the conjugate of the denominator
.
<em>Step 2</em>. Then you must apply the Distributive property in the numerator.
<em>Step 3</em>. You must apply the following property in the denominator:
Therefore, applying the procedure shown above, you get:

<em>Step 4</em>. You can observe that the expression can be simplified even more. Since:

You get:

If we assume the number of polo shirts have been sold is x, the number of casual shirts have been sold will be 4x.
x*18+4x*9=$1080
(18+36)x=$1080
54x=$1080
x=20
The number of casual shirts have been sold is 4*20=80
The area of the triangle extension is 12, because the total side length it is on is 18, and the segments to the sides of the triangle are 6 each, meaning 18-12=6, the height of the triangle. The base is given as 4, so 1/2(4x6)=24/2=12.
Add this to the area of the rectangle, 9x18=162, and 162+12=174.
The area is 174.