Angle and strain have no dimensions. Why?

Explanation

To understand why angle and strain have no dimensions, we can analyze each concept step by step.

### Step 1: Understanding Angle
1. **Definition of Angle**: An angle is formed by two rays (or lines) that meet at a common point (the vertex). The most common unit for measuring angles is radians.
2. **Formula for Angle**: The angle (θ) can be defined as the ratio of the length of an arc (l) on a circle to the radius (r) of that circle:
\[ \theta = \frac{l}{r} \]
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