Google Classroom
GeoGebraGeoGebra Classroom

Construct a Slope Triangle

Create the following construction of a slope triangle. Afterwards, use your construction in order to work on the following tasks.

Construction steps

1.Toolbar ImageCreate two sliders for m and b. Hint: Use the default values for the slider interval of -5 to 5.
2.Enter the equation of a line y = m*x + d into the Algebra Input and press the Enter key.
3.Toolbar ImageCreate the intersection point of the line and the y-axis. Note: The name of the intersection point is A.
4.Toolbar ImageCreate a line through point A that is parallel to the x-axis.
5.Toolbar ImageCreate a point B on the parallel line.
6.Toolbar ImageCreate a line through point B that is perpendicular to the x-axis.
7.Toolbar ImageIntersect these two new lines. Note: The name of the intersection point is C.
8.Toolbar ImageDraw the slope triangle ABC.
9.Change the names of the two legs of the slope triangle to Δy and Δx.
10.Show Name & Value of the legs of the slope triangle by changing the Labeling setting on tab Basics of the Properties dialog.

Tasks

Change the values of the sliders m and b, so that you can successively explore the following lines: (1) y = 2x + 1 (2) y = 3x - 2 (3) y = -x + 2 Task 1: For each of the lines above, move point B and write down the values of Δy and Δx for at least four different slope triangles. Note: Two of your slope triangles should be on the right and two on the left side of the y-axis. Task 2: For each of your slope triangles, calculate the ratio of its two legs and compare the four resulting values for each line.