TI-Nspire App Tutorial

Constructing an Isosceles Triangle

Summary

• In this tutorial, you’ll be constructing an Isosceles Triangle. The steps in the tutorial include:– Creating a Geometry Window.– Constructing a line segment and finding its

midpoint.– Creating a perpendicular line at the midpoint.– Constructing the triangle.– Measuring its side lengths and base angles.

Create a Geometry Window

Click on the + tool to activate this menu.

Create a Geometry Window

This is a blank Geometry Window.

Construct a Line Segment

Click on Menu and select Points & Lines > Segment.

Construct a Line Segment

Press once to define the left endpoint. Then press again to define the right endpoint. Make sure it’s horizontal.

Find the Midpoint

Press Menu and click Tools > Measurement > Midpoint.

Find the Midpoint

Press on the segment to create the midpoint.

Construct a Perpendicular Line

Click on Menu and press Perpendicular.

Construct a Perpendicular Line

Press on the Midpoint. You can also extend the perpendicular line by clicking and dragging it.

Construct the Triangle Sides

Press on Menu and click Tools > Points & Lines > Segment.

Construct the Triangle Sides

Construct the first side by clicking on one endpoint at the base and creating one on the perpendicular line.

Construct the Triangle Sides

Press on the Segment Tool again.

Construct the Triangle Sides

Construct the second side by clicking on the endpoint on the perpendicular line and the other endpoint on the base.

Measure the Side Lengths

Press Menu and Click Tools > Measurement > Length.

Measure the Side Lengths

Click on a side length. You’ll see the measurement, which you can move to a different part of the screen.

Measure the Side Lengths

Press on Menu and Select Length again.

Measure the Side Lengths

Measure the other side. Note that they are congruent.

Measure the Base Angles

Press on Menu and Select Angle.

Measure the Base Angles

Click on the highlighted points to measure this base angle.

Measure the Base Angles

Click on Menu and Angle to measure the other base angle.

Measure the Base Angles

Click on the highlighted points to measure this base angle. Notice the base angles are congruent.

Manipulate the Triangle

Click on any of the vertices of the triangle to manipulate. Notice it maintains congruent sides and base angles.