ACT SAT Math Formulas With 100% Marking Scheme

ACT SAT Math Formulas With 100% Marking Scheme Vertical Angles - ANSWER Formed by 2 intersecting lines or segments. Always congruent. Supplementary Angles - ANSWER Two angles that form a line and add up to 180°. Right Angle - ANSWER An angle that measures 90°. Complimentary Angles - ANSWER Two angles that add up to 90°. Alternate Interior Angles (Parallel Lines) - ANSWER Ex. 3 & 6 are congruent Alternate Exterior Angles (Parallel Lines) - ANSWER Ex. 1 & 8 are congruent Corresponding Angles (Parallel Lines) - ANSWER Ex. 1 & 5 are congruent Same Side Interior Angles (Parallel Lines) - ANSWER Ex. 3 & 5 add up to 180º Area of a Triangle - ANSWER A=½(Base)(Height) A=½bh Triangle Inequality Theorem - ANSWER The sum of the 2 shortest sides of a triangle is always greater than the length of the third side. Equilateral Triangle - ANSWER A triangle in which all three sides are equal and all three interior angles are 60°. Isosceles Triangle - ANSWER A triangle with two equal sides. Base angles (angles across from the congruent sides) are also equal. Proportionality in Triangles - ANSWER In every triangle, the longest side is opposite the largest angle and the smallest side is opposite the smallest angle. Pythagorean Theorem - ANSWER Used to find the missing side of a right triangle. "c" is always the length of the hypotenuse. a²+b²=c² Similar Triangles - ANSWER Triangles that have the same angle measures but different side lengths. Solve by setting up a proportion. 45-45-90 Special Triangle - ANSWER Always in the ratio 1:1:√2 Isosceles right triangle 30-60-90 Special Triangle - ANSWER Always in the ratio 1:√3:2 Pythagorean Triple - ANSWER Three integers that, as side lengths of a triangle, form a right triangle. Ex. 3/4/5 or 5/12/13 Degree Measure of a Triangle - ANSWER The inside angles of a triangle always add up to 180°. Area of a Circle - ANSWER A=πr² Degree Measure of a Circle - ANSWER The central angles of a circle add up to 360°. Circumference of a Circle - ANSWER C=2πr or C=πd Area of a Sector (Circle) - ANSWER (n/360)(πr²), where n is the central angle. Arc Length of a Sector (Circle) - ANSWER (n/360)(2πr), where n is the central angle.