Notes cover how to measure curved distances on circles, relate side lengths in right and similar triangles, and apply linearized trigonometric approximations for very small angles. # 🧭 Index - [[Arc Length of Circles]] - Length of a circular arc of radius - [[Pythagorean Theorem]] - In a right triangle, the squares of the legs sum to the square of the hypotenuse - [[Similar Triangles]] - Triangles with equal corresponding angles and proportional side lengths - [[Small Angle Approximation]] - Approximation for very small angles