Geometry Unit 9.4+

What is the formula for this angle relationship?

angle = ½ (arc + arc)

What is the formula for this angle relationship?

angle = ½ (big arc - little arc)

What is the formula for this angle relationship?

angle = ½ (arc)

What is the formula for this segment relationship?

a x b = c x d

What is the formula for this segment relationship?

a(a + b) = c(c + d)

What is the formula for this segment relationship?

a² = b(b + c)

How do you convert Radians → Degrees?

Multiply by $\frac{180}{\pi}$

How do you convert Degrees → Radians?

Multiply by $\frac{\pi}{180}$

What is the formula for the area of a circle?

A = $\pi$ r²

How do you find the circumference of a circle?

C = 2$\pi$ r² or C = d$\pi$

What is the formula for arc length in radians

s =$\theta$ r

What is the formula for arc length in degrees

a = $\frac{\theta}{360}$ x 2$\pi$ r²

What is the formula for sector area in radians

A = ½ $\theta$ r²

What is the formula for sector area in degrees

A = $\frac{\theta}{360}$ x $\pi$ r²