Question

The two figures are similar. The area of the smaller trapezoid is 771. The ratio of the smaller trapezoid to the bigger trapezoid is 28:64. What is the area of the bigger trapezoid?
a) 4,096 b) 4,028 c) 784 d) 21

Answer 1

Is there missing info from the question?

Answer 2

Yes my bad! What is the area of the bigger trapezoid?

Answer 3

Haha alright give me a min or two :)

Answer 4

Thank you!

Answer 5

B :)

Answer 6

Sorry, I took a bit longer than I thought. I was getting help on my own question.

Answer 7

It's fine, thank you so much!

Answer 8

No problem. Do you need to know how to do it, or are you okay?

Answer 9

Can you please explain it. :)

Answer 10

Sure thing!

Answer 11

@kristinalgarcia I already showed you how to do basically the same question.

Answer 12

Yes I'm aware of that but when I did it with the way you showed me on this problem the answer I got was not an answer choice.

Answer 13

Okay so they gave you the are of the *similar* trapezoid which was 771.
And the ratio was 28:64.

So, 28/28=1 , and 64/28 = 2.28571429...
When you square 2.28... : (2.285...)^2 , you get 5.2244... which is the ratio of the areas of the similar trapezoids.

So, the area of the bigger trapezoid is 5.2244... times bigger than the smaller one:
771(5.2244...) = 4,028.0816... => 4,028

Answer 14

Just multiply by the square of the scale factor:
\[\large 771\times(\frac{64}{28})^{2}=you\ can\ calculate\]

Answer 15

Now I see what I did wrong. @kropot72

Answer 16

@kristinalgarcia The way that I showed you gives one of the answer choices.

Answer 17

Yep, ^ that is an easier, much more efficient way of solving it, provided you have a graphing calculator or sufficient calculator app. I can't do that on my phone, so I did it an alternate way, but both will give you the same answer! :)

Answer 18

@Thatsodan Thank you!

Answer 19

Of course!