Answer:
30.3m^2
Step-by-step explanation:
I started off by finding the area of the semi circle. The formula πr^2 divided by 2. The radius of the circle is 2 because it is half of the diameter which is 4. So π(2)^2 divided by 2 is 6.3.
Next I broke apart the the shape into a rectangle and a triangle for simplicity sake. So doing this I had to know where to cut and if you look at the top of the figure it shows 2m for the length at the top. So I put a vertical line there. Thus changing the 10m on the bottom to a 8m section and a 2m section. So the rectangle's area will be the length times the height which is 2x4=8.
The triangle's area can be found with the equation BH/2 and we the 8 base we found and a height of 4 it is 8x4/2. Which ends up as 16.
Finally you add up all three area's that you found 8+16+6.3=30.3
Answer: Definition of Vertical Angles.
we are given
BE=x
ED=x+10
AE=x+1
EC=x+3
we can see that two chords AC and BD are intersecting inside the circle
so, we can use property

now, we can plug values

now, we can multiply them

now, we can move all terms on left side


...............Answer
Answer: 
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Explanation:
r = number of red pens
4r = cost of buying r red pens
example: if r = 10, then 4r = 4*10 = 40 is the total cost of buying 10 red pens
If John buys r red pens, then he must buy 20-r black pens so that r and 20-r add to 20.
John buys 20-r black pens, and at $5 each, so it will cost 5(20-r) dollars for just the black pens alone.
In total, John spends 4r + 5(20-r) dollars for all the pens (red & black)
We want $92 be the most he spends. This is the ceiling or highest value possible.
Therefore,

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Extra info:
If you want to solve for r, then

distribute

add r to both sides

subtract 92 from both sides


So John must buy at least 8 red pens. The most he can buy is 20 red pens since he wants 20 pens total.