Question

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

Answer 1

@ganeshie8

Answer 2

do u knw the slope formula ?

Answer 3

Y2-Y1/X2-X1

Answer 4

yes good :)
before we apply it, have a look at diagram

how many parallel line pairs do u see ?

Answer 5

2?

Answer 6

I see 3 parallel line pairs :-
1) AB || DE
2) AC || DF
3) you tell me

Answer 7

I see 3 parallel line pairs :-
1) AB || DE
2) AC || DF
3) BC || EF

Answer 8

fine ?

Answer 9

ok now what do I do

Answer 10

Fine slope of two segments in each pair,
and see if u get same value

Answer 11

For first pair :-
1) AB || DE

slope of AB = ?
slope of DE = ?

Answer 12

hold on(:

Answer 13

okie take ur time

Answer 14

I got -6 and -3...

Answer 15

@ganeshie8

Answer 16

you forgot the bottoms....

you should get -6/0 and -3/0

Answer 17

both are UNDEFINED (cuz 1/0 is undefined in algebra)
so, the slope of both segments AB and DE is same = UNDEFINED

Answer 18

Next find slopes for segments in second pair,
and see if u get same or not

Second pair :-
2) AC || DF

slope of segment AC = ?
slope of segment DF = ?

Answer 19

I got -1 for both of them

Answer 20

you should get +1 for both of them

Answer 21

just check ur signs once quick :)

Answer 22

oh yes lol my bad it equals to be 1

Answer 23

A = (-5, 8) C = (-11, 2)
x1 y1 x2 y2


slope = Y2-Y1 / X2-X1

= 2-8 / -11--5

= -6/ -11+5

= -6/-6

= 1

Answer 24

simplarly, slope of DF also will be 1

so for this pair,
we have proved that slope of AC = slope of DF, sincs AC || DF

Answer 25

next, work the slopes for segments in 3rd pair :-
3) BC || EF

slope of BC = ?
slope of EF = ?

Answer 26

0/6 and 0/3 which makes these two slopes undefined. Correct? @ganeshie8

Answer 27

for slopes BC and EF