Question

17th Street, 18th Street, 19th Street, and 20th Street are parallel streets that intersect 1st Avenue and 2nd Avenue. How long is 2nd Avenue between 18th Street and 17th Street, to the nearest foot?

A. 625 ft
B. 655 ft
C. 671 ft
D. 683 ft

Answer 1

@jigglypuff314

Answer 2

This is really tough to understand, sorry. I don't get how I am supposed to set this question up?

Answer 3

I think this would be proportions
so like 380 over 600 = 425 over x

Answer 4

Oh, I didn't even notice it said "to the nearest foot" I figured I was doing it wrong! LOL thank you so much

Answer 5

can u help with this question?? @pitamar

Answer 6

Ok, do you know what similar triangles are?

Answer 7

no i forget everytihng about triangles real easy

Answer 8

do you want a video maybe?

Answer 9

all i know is wen they are like equal measures and angles i dont think a video is really necessary

Answer 10

thye have to be two triangles

Answer 11

Here we have two triangles with same angles (as best as I can draw..)
Because they have the same angles then they have the same 'shape'. However you can see that their sizes are different. so same shape, once big and once small

Answer 12

okkk

Answer 13

Now, the idea is that in the shape there is some proportion between the sides and it doens't matter what their real lengths are. If it is the same shape then the proportions are the same.
So for example if we have:

Answer 14

do we like cross multiply with fractions??

Answer 15

then if we know that the triangles are similar triangles (have the same shape) then we can say that the proportion of the sides is the same. So if we know from the left triangle that the bottom side is double the left side then we can apply this on the right triangle as well and say \(x = 2 \cdot 2 = 4\)

Answer 16

you can say so. we can say on both triangles that the proportion is the same:
$$
\frac{10}{5} = \frac{x}{2}
$$and we can use cross multiplying to find \(x\):
$$
10 \cdot 2 = x \cdot 5\\
2 \cdot 2 = x\\
x = 4
$$

Answer 17

so how can we set up the equation/ fraction for the problem??

Answer 18

Alright, so let me draw it sec

Answer 19

we are asked to find this length: