Geometry Flashcards
Pythagorean Triplets
{3, 4, 5}
{5, 12, 13}
{8, 15, 17}
{7, 24, 25}
Hypotenuse of an Isosceles (45°-45°-90°) Right Triangle
Hypotenuse = √2*(leg)
30°-60°-90° triangle hypotenuse?
hypotenuse = 2 * (short leg)
30°-60°-90° triangle long leg?
long leg = √3 * (short leg)
Area of equilateral triangle?
Area of equilateral triangle = (S^2√3)/4
Parallelogram properties?
1) parallel opposite sides
2) equal opposite sides
3) equal opposite angles
4) diagonals bisect each other
Rhombus properties?
1) the big four of parallelogram properties
2) all four sides are equal
3) Diagonals are perpendicular
Rectangle properties?
1) the big four of parallelogram properties
2) four angles equal to 90
3) Diagonals are congruent
Sum of angles in an n-sided polygon
(n - 2) * 180°
relationship btw diameter d and radii r
diameter d = 2r (radii)
circumference of a circle?
c = πd or c = 2πr
Area of a circle?
A = πr^2
area of sector proportion
area of sector/area of circle = angle/360
Arclength proportion
arclength/circumference = angle/360