# ELM Study Guide Geometry 1

 Complementary Angle Sum equals 90o Supplementary Angle Sum equals 180o Perpendicular Line Intersection forms right angle Transversal When 2 lines are cut by 3rd line, 3rd line is a transversal Scalene Triangle No equal sides & no equal angles Isosceles Triangle -2 equal sides - If you know value of 1 equal side, you can find out value of all angles Equilateral Triangle - All sides & angles are equal - Measure of each angle is 60o Right Triangle The side opposite of the right angle is call hypotenuse 30-60-90 Triangle - It is an equilateral triangle cut in middle - The side opposite the 90o angle is always twice as long as the side opposite the 30o angle. - The side opposite the 60o angle is always √3 times as long as the side opposite the 30o angle 45-45-90 Triangle - Lives a double life: it is both an isosceles & right triangle - The side opposite the 90o angle is always √2 times larger than the two equal sides that sit opposite the 45o angles The Pythagorean Theorem c2 = a2 + b2 - Pythagorean Triples: {3,4,5}, {5,12,13}, {8,15,17}, {7, 24, 25}, {9, 40, 41}. Similarity of Triangles Similar - of the same shape (Proportional) Congruence Two triangles that are IDENTICAL. - Two triangles are congruent if they meet these: Side-Side-Side(SSS) Side-Angle-Side(SAS) Angle-Side-Angle(ASA) Perimeter of Triangle Sum of lengths of triangle;s three sides Area of Triangle 1/2 Base x Height Polygon Two-dimensional figure with 3 or more straight sides Perimeter of Polygon Sum of lengths of its sides Number of Degrees Polygons Hold 180o x (n-2)- Ex. Triangle 180o x (1) = 180o Parallelogram 4 sided figure(quadrilateral) whose opposite sides are parallel. - Opposite sides are equal in length- Opposite angles are equal- Adjacent angles are supplementary- Diagonals bisect eachother Rhombus Parallelogram where all 4 sides are equal in length Area of Parallelogram (Base x Height) well....(Base x Altitiude) Trapezoid One pair of sides is parallel while other is not Area of Trapezoid A = 1/2 (b1 + b2) x h Circumference of a Circle 2πr Area of Circle πr2 Arc of Circle Line segment that is wrapped AROUND the circle with 2 points Chord of Circle STRAIGHT line segment ACROSS the circle with 2 points Authorgerardcb ID149704 Card SetELM Study Guide Geometry 1 DescriptionELM Study Guide Geometry 1 Updated2012-04-24T04:09:20Z Show Answers