Similar Triangles and Slope

 Slope

Today we will practice on how to find slope from two points.

Slope is M

M=Rise over Run

Rise/Run

When you see two ordered pairs (points) and you need to find slope look for RISE/RUN. You need to remember that the first point (you pick) is your (X1, Y1) and the second point (you pick, different from first) is your (X2, Y2). Then you subtract them, the subtraction is in the formula it HAS TO STAY there unless you have a double negative.

Multiple Choice

What is the slope for these two points, (2, 3) and (6, 4)?

• 3/4

• 1/2

• 1/4

What happens if I have a negative point?

What changes in the formula?

Do you remember what changes if you see a negative minus a negative Y2=-4 and Y1=5

ex. 5-(-4)?

Changes to a positive!!

Now you try

Multiple Choice

What is the slope of the line passing through these two points (-9, -3) and (7, -7)?

• -

  $-\frac{1}{4}$

• $\frac{1}{4}$

• $-\frac{1}{2}$

• $\frac{1}{2}$

Multiple Choice

Find the slope of the line passing through the points (2, 5) and (8, -4).

• $\frac{1}{4}$

• $-\frac{3}{2}$

• $-\frac{3}{4}$

• $\frac{1}{2}$

Let's Review the 4 slopes

• Positive (positive slope; left to right line goes upward)

• Negative (negative slope; left to right line goes downard)

• Zero (where the y-coordinates are the same, zero slope (goes left to right; horizontally))

• Undefined (where the x-coordinates are the same, undefined (goes up and down; vertical))

Your turn!!

You have a Google form in Classroom to try, (3) questions. Put your skills to the test, you CAN do it!!