Answer:
<em>I</em><em> hope</em><em> it's</em><em> helps</em><em> you</em>
<em>have</em><em> a</em><em> nice</em><em> day</em>
<span>an</span><span> = </span>a<span>n–1</span><span> + 21 the answer is c
</span>
To determine the area if the circle, you must know the diameter or the radius of a circle.
If you know the radius of a circle, use this as your formula. Remember: Pi (the greek symbol thingy) is equal to 3.1415. (A is equal to area of the circle and r represents the radius)

If you know the diameter, just divide the diameter to get the radius then use the same equation.
Answer:
I would say parallelogram. So the rectangle still fits but more shapes can be applied.
16+24xy+9y2 that is what I got