## Formulas

 Geometry Formulas Perimeter P = sum of sides Area of a triangle A = ½bh Area of a rectangle A = lw Area of a parallelogram A = bh Area of a trapezoid A = ½·(b1 + b2)·h Area of a circle A = πr2
 Word Problem Formulas Distance Distance = rate X time Interest Interest = principal X rate X time Compound Interest Work accomplished work accomplished = (rate of work) X (time worked)
 Graphing Formulas Distance (for graphs) Midpoint Slope Slope-Intercept Form y = mx + b
 Quadratic Equations Standard Form ax 2 + bx + c = 0 Difference of squares x 2 - b 2 = (x + b)(x - b) Quadratic formula Conic Sections Circle Centered at (h, k) with a radius of r: (x - h)2 + (y - k)2 = r 2 Ellipse Centered at (h, k) with its major axis parallel to the x-axis: Centered at (h, k) with its major axis parallel to the y-axis: Parabola If parabola opens vertically: y = a(x - h)2 + k If parabola opens horizontally: x = a(y - k)2 + h Hyperbola If transverse axis is horizontal: If transverse axis is vertical: Sequences and Series Arithmetic Sequence an = a1 + (n - 1)d Geometric Sequence an = a1 r n-1 Arithmetic Series Geometric Series 