3.3 Properties of Slopes

Have you ever stood at the top of a ski hill and

read the signs?Bunny RunMain StreetWipe OutTerminator

What do these signs tell you?

They are all descriptions of how steep (dangerous) each hill is.

This is all you need if all you are doing is snowboarding.

What if you were an engineer and you wanted to build a roller coaster

How would you describe the steepness of these rides?

Engineers have created a mathematical measure for the

steepness of a line

Slope: The measure of a line’s steepness

Rise

Run

Slope = Rise

Run

Therefore, the steeper the slope, the greater the number…

Find the slope of the horizontal line:

Slope = Rise

Run

= 0cm

10cm= 0

0cm

10cm

lines

Parallel lines are straight and never meet, like tracks

Find the slopes of the parallel line segments:

(2,0)

(11,3)(1,2)

(10,5)

L1

L2

X

Y

(2,0)

(11,3)L1

X

Y

(1,2)

(10,5)

L2

X

Y

From this example, it can be stated that

The slopes of parallel lines are equal!

Pg 1241-3, [4,5]a,c6a,c,e8a, 910,11