FIND THE AREA OF THE TRIANGLE

Which is a reasonable estimate of the amount of water in a small, inflatable pool used by children?

Need on this geometry question. explain how you did it.

What is the explicit formula for this sequence? -7, -4, -1, 2, a.) an = 8 + (b - 1)3 b.) an = -7 + (n - 1)3 c.) an = 3 + (n -1) (-7) d.) an = -7 + (n - )