Geometry 5-3a GeoGebra Primer: Circumcenter & Incenter

By Matt Richardson
Last updated about 3 years ago
13 Questions
Instructions: Interact with this applet for a few minutes, then respond to the items that follow.

Be sure to change the locations of the triangle's white vertices both before and after sliding the slider.

Exploration: What can you conclude about the three smaller white points? What are they? How do you know?

Exploration: What do you know about the blue circle? How does it relate to the triangle?

Vocabulary: The blue point is said to be the circumcenter of the triangle. What do you think circumcenter means?

Exploration: What do you know about the point where the brown lines intersect? How does it relate to the triangle? How does it relate to the blue circle?

Exploration: What is the measure of each gray angle? Enter only a number.

Vocabulary: The circle is said to be circumscribed about the triangle. What do you think circumscribed means?

Exploration: What do you know about the brown lines. What are their relationships to the triangle?

Instructions: Interact with this applet for a few minutes, then respond to the items that follow.

Be sure to change the locations of the triangle's white vertices both before and after sliding the slider.

Exploration: What can you conclude about the three black line segments? How do they relate to each other? How do they relate to the triangle?

Exploration: What is the measure of each gray angle? Enter only a number.

Exploration: What do you know about the black point? How does it relate to the triangle? How does it relate to the circle?

Exploration: What do you know about the blue circle? How does it relate to the triangle?

Vocabulary: The circle is said to be inscribed in the triangle. What do you think inscribed means?

Vocabulary: The black point is said to be the incenter of the triangle. What do you think incenter means?