Question

The figure below is a trapezoid with parallel sides that measure 1.7 feet and 2.1 feet. The height of the trapezoid is 12.01

The area of the trapezoid was then doubled. What change in the dimensions of the original trapezoid could have been made to double the area?
Select one:
A. The height was doubled.
B. Both parallel sides were quadrupled.
C. The height was quadrupled
D. One parallel side was doubled and the other was halved.

Answer 1

"The figure below" hints that there is an illustration, a picture, that came with this problem. Where is it? Alternatively, draw your own picture; use the Draw utility, below.

Answer 2

Sorry about that @mathmale

Answer 3

Many thanks for posting the figure. You definitely have a trapezoid here. What is the formula for the area of a trapezoid?

Answer 4

2h\[A=\frac{ a+b }{ 2 }h\]

Answer 5

forget the 2h at the top

Answer 6

@mathmale

Answer 7

\[A=\frac{ a+b }{ 2 }h\] is correct. There's no "2h at the top."

Answer 8

Yup. But I already know that. What I don't know is, "What change in the dimensions of the original trapezoid could have been made to double the area?"

Answer 9

One way would be to double the 'height,' h, right?

Answer 10

Or you could double both a and b.

Answer 11

But I need to find 1 way.

Answer 12

Take your pick, or invent a third way and take that one.

Answer 13

Ok, I'll try both

Answer 14

If I double the height, I get 45.6, which is not the correct answer.

Answer 15

\[A=\frac{ a+b }{ 2 }h\] is the correct formula for the area of this trapezoid.

Answer 16

I found the answer! it's A.

Answer 17

Using the given lengths, the area is \[A=\frac{ 1.7+2.1 }{ 2 }12.01=?\]

Answer 18

I just messed up the first volume

Answer 19

Glad you have the right answer now. (But you're dealing with area, not with volume).