SOLUTION: Directions: write an algebraic expression to describe each situation. Then identify the terms, coefficients, constants, and factors. I think the teacher also said to simplify if po

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Question 892046: Directions: write an algebraic expression to describe each situation. Then identify the terms, coefficients, constants, and factors. I think the teacher also said to simplify if possible.
1/2h(b1+b2) Trying to find the area of a trapezoid. The teacher gave them this expression, but we don't know how to solve it. Can you help us?
Also, 2pi times radius squared + 2 pi times radius times the height. I had to write it this way since I don't have a pi sign. Trying to find the surface area of a cylinder.
Answer by josgarithmetic(39838) (Show Source):
You can put this solution on YOUR website!
You almost have the correct formula for area of a trapezoid. You should use parentheses in plain text to show it without any misunderstanding.
area of trapezoid, , also included the code tags for this site to render the subscripts. The plain text here is (1/2)h(b[1]+b[2]).
The subscripted variables are the "bases" of the trapezoid, which are the two parallel opposite sides. The formula uses THE AVERAGE of the bases and the height; in the same way that a rectangle uses THE base and the height.

The surface area for a cylinder not including any top or bottom could be stated in words, two pi times radius times height. If you want to include the circular top and bottom, then the wording could be two pi multiplied by radius multiplied by height, plus twice the product of pi and r squared. Look in a textbook (geometry or some algebra books) or look in another good reference source.

Formula for cylinder area (no top nor bottom),

Formula for cylinder (with top and bottom),

r is radius
h is "height" or how long from top to bottom
pi is irrational number approximately 3.141592...