3-3 - Slope and

similar triangles

X

Y a

cb

d e

Write a proportion to compare the rise to the run for each of the similar slope

triangles

1

2riserun

Triangle # 1

4

2

42

21

riserun

Triangle # 263

21

6

3

bede

proportionacbc

= 42

63

= 21

=

X

YPick 2 points on the line

and find the sloperise run

12

Slope formula

y2 – y1

x2 – x1

(0,2)

(2,3)

(x1, y1)

(x2, y2)

3 – 22 - 0

12 Pick 2 different points

on the line and find the slope of those points

(6,5)

(10,7)

(x1, y1)

(x2, y2)

rise run

24

Slope formula

y2 – y1

x2 – x1

7 - 510 - 6

12

12

24