Vertex
Vertex is a skill on Pengi from Lesson 19: Polygons in Saxon Math, Course 3.
Key Concepts
Property The point where two sides of a polygon meet is called a vertex (plural: vertices ). A particular polygon can be identified by naming the letters of its vertices in order.
Examples In a square named $ABCD$, the vertices are the points $A$, $B$, $C$, and $D$. A pentagon has 5 sides and therefore also has 5 vertices. You can name a triangle with vertices $X, Y, Z$ as $\triangle XYZ$ or $\triangle ZYX$.
Explanation A vertex is just a fancy word for a corner! It's the spot where two straight sides meet up to say hello. To name a polygon, you just play connect the dots with the vertices' letter names, either clockwise or counter clockwise. It's like calling out the stops on a geometric train ride!
Common Questions
What is Vertex?
Vertex is a skill on Pengi from Lesson 19: Polygons in Saxon Math, Course 3.
What grade level is Vertex for?
Vertex is part of the Grade 8 Math curriculum, covered in Saxon Math, Course 3. It is designed for students studying Math at the Grade 8 level.
How can I learn Vertex?
Pengi offers an AI-guided lesson for Vertex that walks you through the key concepts step by step. The lesson is aligned to Saxon Math, Course 3 so the content matches what you see in class.
How do I practice Vertex?
After learning the concept, use the Practice mode to work through targeted exercises on Vertex. The AI adapts to your level and gives feedback on each answer so you can identify and fix mistakes.
Which textbook covers Vertex?
Vertex is covered in Saxon Math, Course 3, specifically in Chapter 2: Number & Operations • Geometry under Lesson 19: Polygons. Pengi's lesson is aligned directly to this textbook so you can follow along with your class.
Is Vertex free to study on Pengi?
Yes, the core Learn and Practice modes for Vertex are available for free on Pengi. No credit card is required to start studying.