“t0” and “t1” specify the range of movement of point A on side CD. The initial default values are t0 = 0 and t1 = 1. During animation, the length of CD is considered to be one unit. The default values specify that movement of point A is from start point C (point where length equals 0) up to end point D (point where length equals 1).

Changing the value of t0 to 0.5, for example, causes point A to move from the middle of side CD to point D. Changing the value of t0 to −1, causes point A to begin at a point outside side CD (in this case, at a point a distance equivalent to the length of side CD) and ending with point D.

Traces:

This item shows the specified trace point. Tapping [Remove] cancels the trace point setting.

3. While the lower window is active, tap C to close the animation editing window.

uTo view an animation table

Note: The steps below continue from the procedure under “To trace a locus of points”.

1.Tap line segment AB, which connects point A with apex B, to select it.

2.Tap uon the toolbar to display the measurement box.

•This displays the measurement of line segment AB in the measurement box.

3.Tap # next to the measurement box.

•This displays a table showing the length of line segment AB for each animation step in the bottom half of the screen.

4.Next, let’s add a column to the table that shows the area of triangle ABE at each step. Perform the steps below.

(1)Draw a line segment that connects point A with apex E.

(2)Select line segment AB, line segment AE, and side BE.

(3)Tap # next to the measurement box.

This adds a column that shows the area of triangle ABE at each step. (As can be seen, the area of triangle ABE does not change even when point A moves.)

Chapter 8: Geometry Application

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