Radians & Sectors

CHAPTER 18

18.1 Degrees and Radians Conversion

$\pi$ radians = 180°

Degrees → Radians: multiply by $\frac{\pi}{180}$

Radians → Degrees: multiply by $\frac{180}{\pi}$

18.2 Arc Length & Sector Area

Measure	Formula (angle $\theta$ in radians)
Arc Length	$l = r\theta$
Sector Area	$A = \frac{1}{2}r^2\theta$

📘 MathsKiller Textbook Series | Chapter 18