Answer:
Step-by-step explanation:
The identities you need here are:
and 
You also need to know that
x = rcosθ and
y = rsinθ
to get this done.
We have
r = 6 sin θ
Let's first multiply both sides by r (you'll always begin these this way; you'll see why in a second):
r² = 6r sin θ
Now let's replace r² with what it's equal to:
x² + y² = 6r sin θ
Now let's replace r sin θ with what it's equal to:
x² + y² = 6y
That looks like the beginnings of a circle. Let's get everything on one side because I have a feeling we will be completing the square on this:

Complete the square on the y-terms by taking half its linear term, squaring it and adding it to both sides.
The y linear term is 6. Half of 6 is 3, and 3 squared is 9, so we add 9 in on both sides:

In the process of completing the square, we created within that set of parenthesis a perfect square binomial:

And there's your circle! Third choice down is the one you want.
Fun, huh?
The correct answer for the question that is being presented above is this one: "Point E." The p<span>oint that represents the vertex of the marked angle is the point E.
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Here is the link of the image: http://assets.openstudy.com/updates/attachments/547f6445e4b03e22bc88fa0f-16cepps-1417634973773-math......
The answer for your question is D
Area of ∆=1/2bh
80yd^2=1/2(b)(10yd)
80yd^2=5yd(b)
80yd^2÷5yd=b
16yd=b