Triangle ABC is similar to triangle DEF. Using the image below, prove that lines BC and EF have the same slope. You must show all of your work to receive credit.

Triangle ABC and DEF are shown. A is at negative 2, 1. B is at negative 2, 4. C is at 1, 1. D is at 4, 2. E is at 4, 4. F is at 6, 2.

Question

Triangle ABC is similar to triangle DEF. Using the image below, prove that lines BC and EF have the same slope. You must show all of your work to receive credit.

 Triangle ABC and DEF are shown. A is at negative 2, 1. B is at negative 2, 4. C is at 1, 1. D is at 4, 2. E is at 4, 4. F is at 6, 2.

anonymous · Answer

@jim_thompson5910 (:

jim_thompson5910 · Answer

If you plot the points, and connect them, you should get this

jim_thompson5910 · Answer

to find the slope of BC, you divide the length of AB over the length of AC

basically slope = rise/run

the slope of BC is negative since it runs downhill as you move from left to right

anonymous · Answer

oh ok so the length of AB would be 3 right ? and then the length of AC would be 3 to right ?

jim_thompson5910 · Answer

correct on both

anonymous · Answer

oh ok so if i diided those both i would get 1 right ?

anonymous · Answer

divide*

anonymous · Answer

@jim_thompson5910  are u there ?

jim_thompson5910 · Answer

so the slope of BC is -1

jim_thompson5910 · Answer

now find the slope of EF

anonymous · Answer

ok so the length of DE would be 2 and then DF would 2 as well right and when i divide them both i get 1

jim_thompson5910 · Answer

make that result negative since the line EF goes downhill as you read left to right

slope of EF = -1

anonymous · Answer

oh ok so would this be the answer ??

jim_thompson5910 · Answer

yes you have shown that 

slope of BC = slope of EF

jim_thompson5910 · Answer

both are negative 1

anonymous · Answer

oh ok thank you so much ^-^

jim_thompson5910 · Answer

np

anonymous · Answer

do u mind helping me with just two more ?

jim_thompson5910 · Answer

I'll help with one more