At the end of this section you should be able to:

1. Define strain at a point

2. Calculate normal strain

3. Calculate shear strain

Strain explains how to quantify deformation at a point using normal strain and shear strain. In this section you will define strain, compute normal strain from changes in length and geometry, and connect the equations to clear visual interpretations, including small angle approximations (similar triangles) and large angle deflection cases. You will also calculate shear strain from the change in angle between line elements, including using the dot product to determine angles accurately, with Mathematica code provided to support calculation and checking.