Geometry 5-6a GeoGebra Primer: Triangle Inequalities

By Matt Richardson
Last updated about 3 years ago
8 Questions
Interract with the applet for a few minutes. Refresh the page to restart the applet.
Use the Angle tool to display angle measures by selecting the triangle.
Use the Distance or Length tool to label each side length by selecting pairs of consecutive vertices.
Set a scalene triangle in the applet above with labels showing its angle measures and side lengths before responding to the items that follow.

Exploration: In the triangle you set in the applet, which angle has the greatest measure?

Exploration: In the triangle you set in the applet, which side length is the greatest?

Exploration: How is the largest angle in the triangle related to the longest side of the triangle?

Exploration: In the triangle you set in the applet, which angle has the smallest measure?

Exploration: In the triangle you set in the applet, which side length is the smallest?

Exploration: How is the smallest angle in the triangle related to the shortest side of the triangle?

Reasoning: Is there a similar relationship between the middle angle measure and the middle side length? What is that relationship?

Extension: These relationships between angle measures and side lengths extend to all triangles. Write your own "theorem" to summarize the relationships.