  School of Logical Thinking Tests Examples - Demo Elementary Mathematics High School Placement Placement College Test ACT SAT Flash Games ACT ACT Assessment Test Description English Test Mathematics Test Reading Test Science Test Writing Test SAT Early Mathematics Study Guide Arithmetic Algebra Geometry Trigonometry A, B, C, D, E, F – vertices of polygon; angles A , B , C , D, E , F – angles of polygon; segments AC, AD, BE etc. are diagonals; AB, BC, CD, DE, EF, FA – sides of polygon; a sum of sides lengths AB + BC + … + FA is called a perimeter of polygon and signed as p (sometimes – 2p, then p – a half-perimeter). We consider only simple polygons in an elementary geometry, contours of which have no self-intersections ( as shown on Fig.18 ). If all diagonals lie inside of a polygon, it is called a convex polygon. A hexagon on Fig.17 is a convex one; a pentagon ABCDE on Fig.19 is not a convex polygon, because its diagonal AD lies outside of it. A sum of interior angles in any convex polygon is equal to 180 ( n – 2 ) deg, where n is a number of angles (or sides) of a polygon. View My Stats Privacy Statement © 2006 MathPlusFun, All Rights Reserved