# Math Plane Geometry

 The flashcards below were created by user Rayna on FreezingBlue Flashcards. :represented by a dot point :a group of points having to endpoints line segment :describes segments or angles of the same length, shape or size congruent  ≃ :a group of points having no endpoints line (A line extends indefinitely in two opposite directions.) :a group of points having one endpoint ray (A ray extends indefinitely in one direction.) :two rays that share a common endpoint angle : a common endpoint where two rays or sides of a polygon meet, usually labled with capital letters vertex : a 90 degree angle with a square corner right angle :lines that cross each other at some point intersecting lines :intersecting lines that form four right angles perpendicular lines :lines that never intersect parallel lines :does not have a point of intersection simple closed shape symbol :have the same shape but not the same size similar shapes  ˜ :simple closed shape made up of line segments polygon :a three sided polygon triangle :a four-sided polygon quadrilateral :a quadrilateral having opposite sides that are parallel parallelogram : a parallelogram having four right angles rectangle : a rectangle having four congruent sides square : a parallelogram having four congruent sides rhombus :a quadrilateral having only one set of opposite sides that are parallel trapezoid :a five sided polygon pentagon :a six-sided polygon hexagon :a seven-sided polygon heptagon :an eight-sided polygon octagon Formula Perimeter Rectangle/parallelogram P = 2l + 2w Formula Perimeter square P = 4s Formula Perimeter Triangle P = a + b + c Formula Area Rectangle A = bh 1 square foot (sq. ft.) =        sq. in. 144 sq. in. 1 acre (a.) =      sq. ft. 43,560 sq. ft. 1 square Yard (sq. yd.) =     sq. ft. 9 sq. ft. 1 square mile (sq. mi.) =     acres 640 acres Area Square A = s2 Area of Parallelogram A = bh Area of Triangle A = b h       21/2 x base x height Area of Trapezoid A = H(b1+b2)          2 Right Angle 900 Formula sides of right triangle Acute Angle Less than 90o Angle that measures more than 90o obtuse angle angle that measures 180o straight angle triangle that has two congruent sides and two congruent angles isosceles triangle triangle that has three congruent sides and angles equilateral triangle Name of an instrument that is used to measure the number of degrees in an angle. protractor Half of a circle is called a? How many degrees is it? semicircle180o The line segment that goes through the center of a circle and has both endpoints on the circle? diameter The length of a straight line drawn from the center to a point on a circle? radius Degrees in a circle? 360o Formulas for circumference of a circle?  distance around a circle = 3.143 1/7 Formula for area of a circle? Formula area of regular polygon AuthorRayna ID267258 Card SetMath Plane Geometry DescriptionGeometry terms, 7th grade Math Abeka Updated2014-09-18T17:51:28Z Show Answers