<p>Buzz Words of Measurement & Geometry Page 1/3 TELLING TIME analog clock - a clock that displays the time of day by the position of hands on a dial digital clock - a clock or watch that shows the time using numbers, not hands 24-hour clock - a method of measuring the time based on the full twenty-four hours of the day, rather than dividing it into two units of twelve hours a.m. – ante meridian (before noon) p.m. – post meridian (after noon)</p><p>LINES point - an exact location in space endpoint – the point at the end of a line segment vertex – the point where two (or more) rays or line segments meet ray - a part of a line that starts at one endpoint and extends forever line – a straight path that extends without end in opposite directions line segment - part of a line with two endpoints congruent – same size or length midpoint – a point that divides a segment into two congruent segments intersecting lines – lines that cross each other perpendicular lines – lines that cross each other at a right angle (90) parallel lines – two lines on a plane that never meet; they are always the same distance apart angle – formed by two rays with a common endpoint degree – a measure for angles ANGLES right angle – an angle that measures 90 obtuse angle - an angle that measures more than 90, but less than 180 reflex angle - an angle that measures more than 180 straight angle - an angle that measures180 angle bisector – a ray that intersects the angle into two equal parts</p><p>SHAPES Page 2/3 polygon – a closed plane figure bounded by three or more line segments regular polygon – a polygon with congruent (equal) sides and angles equilateral triangle – a triangle with three congruent sides and three congruent angles right triangle – a triangle with one right (90) angle isosceles triangle – a triangle with two congruent sides and two congruent angles scalene triangle – a triangle having three unequal sides and three unequal angles quadrilateral – a four-sided polygon square – a quadrilateral with four congruent sides and four 90 angles rectangle – a quadrilateral with opposite sides congruent and four right angles rhombus – a square with no right angles trapezoid – a quadrilateral with two parallel and non-parallel sides parallelogram - a four-sided polygon with two sets of opposite parallel sides pentagon – a five-sided polygon hexagon – a six-sided polygon octagon – an eight-sided polygon decagon – a ten-sided polygon LINE DESIGNATION vertical – in an up and down position, perpendicular to horizontal horizontal – in a side to side position, perpendicular to vertical</p><p>MEASUREMENT perimeter – distance along the outline of a plane shape – measured in linear units (mm, cm, m, km) area – measurement of the number of square units inside the outline of a plane shape – measured in square units (mm2, cm2, m2 ,km2 ) volume – measurement of the space inside a solid – measured in cubic units (mm3, cm3 , m3 , km3) surface area – the total area of all the surfaces of a solid (a 3-dimensional object) TRANSFORMATIONAL GEOMETRY symmetrical - one side is the same as the other; one side can be reflected onto the other side transformation – moving a shape so that it is in a different position, but still has the same size, area, angles and line lengths translation – a transformation that involves a geometric figure moving from one place to another, without rotating or reflecting Page 3/3 reflection – a transformation in which a geometric figure is reflected across a line, creating a mirror image rotation – a transformation that involves a circular movement of a geometric figure; the central point stays fixed and everything else moves around that point in a circle. tessellation - the tiling of a plane using one or more geometric shapes, called tiles, with no overlaps and no gaps. CONSTRUCTION TOOLS protractor – a tool used to measure the degrees of an angle compass – a tool used to draw arcs or circles CIRCLES circle – a plane figure made by drawing a curve that is always the same distance from its center center – the center of a circle is the point inside the circle, from which all points on the circle are the same distance circumference – the distance along the outline of a circle, measured in linear units (mm, cm, m, km) radius – the distance from the center to the edge of a circle; it is half of the circle's diameter diameter – a straight line going through the center of a circle connecting two points on the circumference; it is twice the length of the circle’s radius pi – () – the ratio of the circumference of a circle to its diameter. The symbol for pi is π; the ratio is the same for all circles and is approximately 3.1416 3-D SOLIDS plane – a flat surface that goes on forever in all directions face – any of the individual surfaces of a solid object edge – the line at which two faces of a solid object meet vertex – the point where two (or more) edges meet prism – a solid object that has two identical ends and all flat sides; the cross section is the same all along its length. The shape of the ends gives the prism a name, such as "triangular prism" “rectangular prism” (box or rectangular solid), “hexagonal prism” . . . pyramid – A solid object where: * The base is a polygon (a straight-sided shape) * The sides are triangles which meet at the top (the apex) cube – a solid object with six square faces sphere - A 3-dimensional object shaped like a ball - every point on the surface is the same distance from the center.</p>