初中数学

初中数学，菱形内角和为360度，所有边的长度相等，对边平行，对角相等，等腰梯形，内角和是360°，有两对角相等。

Angles in Quadrilaterals

• Irregular trapezium
• Kite
  • The interior angles add up to 360
  • There are 2 congruent pairs of sides
  • Each pairs consists of equal-length sides that are adjacent(they meet)
  • The diagonals are perpendicular
• Rhombus
  • The interior angles add up to 360
  • All sides have equal length
  • Opposite sides are parallel and opposite angles are equal
  • The diagonals bisect each other at a right angle
• Isosceles Trapezium
  • The interior angles add up to 360
  • It has 1 pair of parallel lines
  • There are 2 pairs of angles that are equall
  • Both pairs of opposites angles are supplementary: they add up to 180
• Parallelogram
  • The interior angles add up to 360
  • Opposite sides are parallel
  • Opposite sides are equal in length
  • Opposite angles are equal (angles a are the same and angles b are the same)
  • Angles a and b are supplementary:they add up to 180
• Square
  • The interior angles add up to 360
  • Each angles is 90
  • All sides have equal length
  • It has 2 pairs of parallel lines