1. The information is not on the reference sheet. Equation of the circle
(x - h)2 + (y-k)2 = r2
Center: (h ,k )
r= radius
Pythagorean theorem
a2 + b2 = c2
Pythagorean triples
3 – 4 –
3 – 4 – 5 (2)
6 – 8- 10
3 – 4 – 5 (3)
Note: Remember to change the
sign for the center coordinate and
find the square root to find the radius
Arc length = Central angle x 2𝝅𝒓
360
Conversion
1 foot = 12 in
Area of a sector = central angle 𝜋 𝑟 2
360
SOH-CAH-TOA
Euler’s Formula= F + V = E + 2
Tetra (4)
Hexa (6)
Octa (8)
Dode (12)
opposite
hypotenuse α
adjacent

2. Area of a Circle: 𝐴=𝜋 𝑟 2
Circumference of a Circle: C = 2πr
Area of a Triangle: 𝐴= 1 2 𝑏ℎ
Area of a Parallelogram: 𝐴=𝑏ℎ
Area of a Regular Polygon: 𝐴= 1 2 𝑎𝑃
Distance Formula:
𝑑= 𝑥 2 − 𝑥 𝑦 2 − 𝑦 1 2
Midpoint Formula:
M= 𝑥 1 + 𝑥 2 2 , 𝑦 1 + 𝑦 2 2
Slope Formula: 𝑚= 𝑦 2 − 𝑦 1 𝑥 2 − 𝑥 1