← Topic 4 · Geometry
AMC 10/12 · Cheatsheet
Topic 4 · Geometry
Chapter 3 · Coordinates & transformations
🖨 Print / PDF
📋 Reference · always available
Distance
d
=
(
Δ
x
)
2
+
(
Δ
y
)
2
d=\sqrt{(\Delta x)^2+(\Delta y)^2}
d
=
(
Δ
x
)
2
+
(
Δ
y
)
2
Circle
(
x
−
h
)
2
+
(
y
−
k
)
2
=
r
2
(x-h)^2+(y-k)^2=r^2
(
x
−
h
)
2
+
(
y
−
k
)
2
=
r
2
Perp. slopes
m
1
m
2
=
−
1
m_1 m_2 = -1
m
1
m
2
=
−
1
Transforms
90
∘
ccw
:
(
x
,
y
)
→
(
−
y
,
x
)
90^\circ\text{ ccw}: (x,y)\to(-y,x)
9
0
∘
ccw
:
(
x
,
y
)
→
(
−
y
,
x
)