(a quick how-to) Wendi Morrison 2010

 Start with data, not necessarily linear. Time (s)Distance (m) Distance vs. Time What was the distance at 35 s? When was the distance 200 m?  Use a straight line to estimate a value between known data.

 Choose the two points that capture 35 s. Time (s)Distance (m) x x  Plot the points to make a triangle.  Label what you know.  Label the triangle sides.  Solve the ratio:  Add x to the lower value: = 125 The triangle is this shape because the graph goes up…  Make a smaller triangle. x Round to the same precision as 35 s.

 Choose the two points that capture 200 m. Time (s)Distance (m) x 40 x 200 Round to the same precision.  Plot the points to make a triangle.  Label what you know.  Solve the ratio:  Add x to the lower value: = 44  Label the triangle sides.  Make a smaller triangle.