Area Formulas
Area of a Triangle
A = (1/2)bh
Circumference of a Circle (in terms d)
C = dπ
Area of a Rectangle
A = bh or A = lw
In a Rhombus, the ___________ intersect at a ______ angle.
diagonals, 90°
30-60-90 Triangle
Formula for L
L = s √ 3
Area of a Rhombus
A = (1/2)(d1d2)
Circumference of a Circle (in terms r)
C = 2π r
Area of a Square
A = s2
In a Rhombus, the ________ bisect each other
Diagonals
30-60-90 Triangle
Formula for H
H=2s
Area of a Trapezoid
A = (1/2)h(b1+b2)
Central Angle of a Polygon
Central Angle = 360°/n
Area of a Trapezoid
A = (1/2)h(b1+b2)
The Apothem is what to a Regular Polygon's Central Angle:
Angle Bisector
Pythagorean Theorem
a2 + b2 = c2
Area of a Circle
A = π r2
Perimeter of a Regular Polygon
P = ns = (number of sides)(side length)
Area of a Regular Polygon
A = (1/2)aP
In a Regular Polygon, all of the sides and angles are
Congruent
45-45-90 Triangle
Formula for H
H = L √ 2
Area of a Parallelogram
A = bh
Three Different Forms of Equation of a Line
y = mx + b
Ax + By = C
y - y1 = m(x - x1)
Area of a Rhombus
A = (1/2)(d1d2)
Formula for Sum of the Interior Angles of a Polygon
Sum = (n-2)180°
Distance Formula
d = √ [(x2-x1)2 + (y2-y1)2]