You have posted 2 separate questions here. Please, next time, separate them with a blank line:
<span>A circle has an area of 81 3.14 units . what is the diameter in terms of 3.14?
I'd prefer you write this as
"</span><span>A circle has an area of 81 pi units . what is the diameter in terms of pi?
Area of a circle = A = pi*r^2. Note that r= diameter / 2. Here, the area is 81 pi square units, or 9^2 * pi square units, which means that the radius is 9 units. The diameter is then 2(9 units) = 18 units.
Your second question, separated from the first, is:
"</span><span>a circle has an area of 81 Pi square units what is the diameter of the circle?"
</span><span>
Use the following formula or formulas: d = 2*r; A = pi*r^2; A = pi*(d/2)^2. Find r first, and then find d.
</span>
<h2>
Answer:</h2>

<h2>
Step-by-step explanation:</h2>
A trapezoid is a quadrilateral where at least one pair of opposite sides are parallel. In a trapezoid, the both parallel sides are known as the bases of the trapezoid. So we have two bases, namely,
. Also, the height
of the trapezoid is the length between these two bases that's perpendicular to both sides. So the area of a trapezoid in terms of of
is:

Since:

The area is:

Cosine(O) = Adj / Hypo
Plug in numbers to find the ratio
Hope it helps
Answer:
A) Divide 20 by 2 and then add 8 to the result
Step-by-step explanation:

Answer:
2.99m-4 (less than or equal to symbol after) 20
Step-by-step explanation:
This would come out too 5 movies because 20-4= 16 16-2.99=5.3 but it is impossible to buy 5.3 movies so you would round it down to 5