1) Use the MIDPOINT

tool to plot the midpoints of any 2 sides of the given triangle.
2) Use the SEGMENT

tool to draw the segment (triangle midsegment) connecting these 2 points.
3) Use ANOTHER TOOL to illustrate this midsegment (MS) is parallel to the 3rd side of the triangle.
4) Measure and display the names lengths of the MS and the side of the triangle the MS doesn't touch.
5) In the algebra view (left side), input [name of MS] / [name of triangle side MS doesn't touch].
6) Move
A, B, and/or
C around to verify the slopes are equal and the ratio MS / 3rd side = 0.5.