ACT MATH STUDY GUIDE questions and answers

Degrees in triangle 180 Degrees in circle 360 Area of triangle 1/2x base x height Area of circle pi x radius to the second power Circumference of circle 2 x pi x radius OR pi x diameter Area of rectangle Base x height Area of parallelogram Base x height Area of square side to the second power Pythagorean Theorem a to the second power plus b to the second equals c to the second power. (C=hypotenuse, only true for right triangles) Slope-intercept form of a line: y=mx + b Point slope form of a line: y - y1 = m (x - x1) Slope formula [between 2 points (x1,y1) and x2, y2)] y2 - y1/ x2-x1 Distance Formula [between 2 points (x1, y1) and (x2, y2)] Square root (x2 - x1) to the second power + (y2 - y1) to the second power Midpoint Formula [between 2 points (x1, y1) and (x2, y2)] (x1 + x2/2, y1 + y2/2) Equation of circle: Case 1: If center is (0,0): x2 + y2 = r2 Equation of circle: Case 2: If center is (h,k): (x-h)2 + (y-k)2 = r2 Logarithm Formula: log base x = y b to the y power equals x sin opposite/hypotenuse cos adjacent/hypotenuse tan opposite/adjacent Volume of a cylinder pie x radius to the second power x height Volume of box V=length x width x height Mean Add all numbers, divide by number of numbers. Median The middle number from small to large, choose median. FOIL First, outside, inside, last (EX: (X-3)(X+2) = x2 + 2x -3x - 6) Number of degrees in n-sided polygon (n-2)(180) Percent Formula is/of = %/100