22 terms

Vital Geometry Formulae

STUDY
PLAY
Area of a Triangle
½(b×h)
Pythagorean Theorem
a²+b²=c²
Sides in a 30°-60°-90° Triangle
1:√3:2
Sides in a 45°-45°-90° Triangle
1:1:√2
Area of a Circle
πr²
Circumference of a Circle
2πr, or πd
Area of a Parallelogram
b×h
Area of a Trapezoid
{½(b₁+b₂)}h
Area of a Kite or a Rhombus
½(d₁+d₂)
Area of a Square
Area of a Regular Polygon
½(p×a)
Sum (in degrees) of the Interiors Angles of a Triangle
180°
Sum (in degrees) of the Interior Angles in an N-Sided Polygon
(n-2)180
Sum (in degrees) of the Exterior Angles in any Polygon
360°
Number of Diagonals that can be drawn in an N-Sided Polygon
½{n(n-3)}
Slope
rise÷run
Midpoint Formula
(xmp, ymp)
Distance Formula
√(x₂-x₁)²+(y₂-y₁)²
Slope-Intercept Form of the Equation of a Line
y=mx+b
Point-Slope Form of the Equation of a Line
y-y₁=m(x-x₁)
Equation of a Circle
(x-h)²+(y-k)²=r²
Hero's Formula
√S(S-a)(S-b)(S-c)