{
 "source": "https://peabody.kids/flashcards/math-angles-lines",
 "id": "math-angles-lines",
 "title": "Angles, Lines and Circles",
 "category": "math",
 "subject": "Math",
 "levels": [
  "3-5",
  "6-8",
  "9-12"
 ],
 "description": "Kinds of angles, angle pairs, lines and the parts of a circle.",
 "tags": [
  "angles",
  "lines",
  "circles"
 ],
 "frontLabel": "Term",
 "backLabel": "Meaning",
 "cards": [
  [
   "Acute angle",
   "Between 0° and 90°"
  ],
  [
   "Right angle",
   "Exactly 90°"
  ],
  [
   "Obtuse angle",
   "Between 90° and 180°"
  ],
  [
   "Straight angle",
   "Exactly 180°"
  ],
  [
   "Reflex angle",
   "Between 180° and 360°"
  ],
  [
   "Full rotation",
   "360°"
  ],
  [
   "Complementary angles",
   "Add up to 90°"
  ],
  [
   "Supplementary angles",
   "Add up to 180°"
  ],
  [
   "Complement of 30°",
   "60°"
  ],
  [
   "Supplement of 110°",
   "70°"
  ],
  [
   "Vertical angles",
   "Opposite angles made by two crossing lines; they are equal"
  ],
  [
   "Adjacent angles",
   "Share a vertex and a side, with no overlap"
  ],
  [
   "Linear pair",
   "Two adjacent angles that form a straight line; add up to 180°"
  ],
  [
   "Corresponding angles",
   "Angles in matching positions at two different crossings of a transversal"
  ],
  [
   "Alternate interior angles",
   "Angles inside the two lines on opposite sides of the transversal"
  ],
  [
   "Alternate exterior angles",
   "Angles outside the two lines on opposite sides of the transversal"
  ],
  [
   "Same-side interior angles",
   "Angles inside the two lines on the same side of the transversal"
  ],
  [
   "Vertex of an angle",
   "The point where the two rays meet"
  ],
  [
   "Angle bisector",
   "A ray that splits an angle into two equal angles"
  ],
  [
   "Protractor",
   "A tool for measuring angles in degrees"
  ],
  [
   "Line",
   "A straight path that goes on forever in both directions"
  ],
  [
   "Line segment",
   "A piece of a line between two endpoints"
  ],
  [
   "Ray",
   "A part of a line with one endpoint, going on forever one way"
  ],
  [
   "Collinear points",
   "Points that lie on the same line"
  ],
  [
   "Coplanar",
   "Lying in the same flat plane"
  ],
  [
   "Parallel lines",
   "Lines in a plane that never meet"
  ],
  [
   "Perpendicular lines",
   "Lines that meet at 90°"
  ],
  [
   "Skew lines",
   "Lines in 3D that do not meet and are not parallel"
  ],
  [
   "Midpoint",
   "The point exactly halfway along a segment"
  ],
  [
   "Perpendicular bisector",
   "A line that cuts a segment in half at a right angle"
  ],
  [
   "Transversal",
   "A line that crosses two or more lines"
  ],
  [
   "Plane",
   "A flat surface that extends forever in every direction"
  ],
  [
   "Center of a circle",
   "The point equally far from every point on the circle"
  ],
  [
   "Radius",
   "A segment from the center to the circle"
  ],
  [
   "Diameter",
   "A chord through the center; the longest chord"
  ],
  [
   "Chord",
   "A segment joining two points on a circle"
  ],
  [
   "Secant",
   "A line that cuts through a circle at two points"
  ],
  [
   "Tangent",
   "A line that touches a circle at one point"
  ],
  [
   "Arc",
   "A piece of the circle's outline"
  ],
  [
   "Minor arc",
   "An arc smaller than a semicircle"
  ],
  [
   "Major arc",
   "An arc larger than a semicircle"
  ],
  [
   "Semicircle",
   "Half a circle; an arc of 180°"
  ],
  [
   "Sector",
   "A region bounded by two radii and an arc"
  ],
  [
   "Segment of a circle",
   "A region bounded by a chord and an arc"
  ],
  [
   "Central angle",
   "An angle with its vertex at the center of a circle"
  ],
  [
   "Inscribed angle",
   "An angle with its vertex on the circle"
  ],
  [
   "Concentric circles",
   "Circles that share the same center"
  ],
  [
   "Congruent circles",
   "Circles with equal radii"
  ],
  [
   "Degrees in a circle",
   "360"
  ],
  [
   "Radians in a full circle",
   "2π"
  ],
  [
   "Degrees in one radian",
   "About 57.3°"
  ],
  [
   "Convert 180° to radians",
   "π radians"
  ],
  [
   "Convert 90° to radians",
   "π/2"
  ],
  [
   "Convert 60° to radians",
   "π/3"
  ],
  [
   "Convert π/4 to degrees",
   "45°"
  ],
  [
   "Convert π/6 to degrees",
   "30°"
  ]
 ]
}