ACT Math Flashcards
1
Q
Circumference of a circle
A
(2•pie)(r)
2
Q
Area of a circle
A
Pie•r^2
3
Q
Central arc
A
A central arc has its vertex at the center of a circle and defines an arc of equal measure on the circles circumference
4
Q
Inscribed angle
A
An inscribed angle is created by extending two straight lines from a point on the circumference of a circle across the circle
5
Q
Inscribed angle= 1/2 central angle
A
Inscribed angle=1/2 arc
6
Q
Midpoint formula
A
(X1+X2/2,Y1+Y2/2)
7
Q
Formula for a circle
A
(X-h)^2+(y-k)^2=r^2
H+K are center coordinates of circle
8
Q
Vertical parabola equation
A
y-k=a(x-h)^2
(h+k) = vertex
9
Q
Horizontal parabola equation
A
x-h=a(y-k)^2
Just swirl the x and y
