Finally, we're getting to geometry. We've been waiting for this and hope you have been, too. The foundation of all geometry is the line--so that's a great place to start. From there we'll move into angles, quadrilaterals, and triangles. Our goal here is to get familiar with the basic concepts, skills, and applications of geometry. So jump in and let's go for a ride!

Angle introduction

What is an angle and how do we label, measure and construct them? Great question. Luckily we have all your answers! To begin our journey towards understanding angles, we'll learn terms like vertex, acute, obtuse, circle arc, circumference, and protractor. These basic angle concepts will get you on the road to angle domination!
Intro to angles
Sal introduces angles and parts of an angle, like the vertex.
Naming angles
Sal names angles based on their vertex and endpoints.
Name angles
Name angles by their vertex, endpoints, or labels.  

Line of symmetry

A line of symmetry for a two-dimensional figure is a line across the figure such that the figure can be folded along the line into matching parts. In this tutorial, we'll identify line-symmetric figures and draw lines of symmetry. Common Core Standard: 4.G.A.3
Intro to reflective symmetry
Sal introduces the concept of an "axis of symmetry."
Identify lines of symmetry and symmetrical figures
Draw and identify lines of symmetry.  Create and identify symmetrical shapes.
Draw lines of symmetry and symmetrical figures
Practice drawing lines of symmetry and creating symmetrical figures.