Friday, December 9, 2011

Engineering Mathematics : Plane Geometry Part 1

Fundamental Principles


Angles

  • Acute angle = less 90 deg
  • Obtuse angle = more than 90 and less than 180 deg
  • Straight angle =180 deg
  • Vertex of the angle is point where two lines meet
  • Supplementary angles have a sum of 180 deg
  • Complementary angles have a sum of 90 deg
  • The base angles of an isosceles (two equal sides) triangle =  60 deg
  • Each angle of an isosceles right triangle = 45 deg
  • Exterior angle of a triangle is the sum of the remote interior angle
  • The sum of the angles of a polygon of n sides = (n-2)180 deg
  • The sum of the exterior angles of any polygon = 360 deg

Congruence of triangle
In geometry,Two triangles are congruent if their corresponding sides are equal in length and their corresponding angles are equal in size

conditions:   (s=side  ; a=angle)
  • s.a.s =s.a.s   (Side-Angle-Side)
  • a.s.a=a.s.a  (Angle-Side-Angle)
  • s.s.s=s.s.s  (Side-Side-Side
  • a.a.s=a.a.s (Angle-Angle-Side)

conguent triangle condition

Two right triangles are congruent if hypotenuse and leg of one hypotenuse and corresponding leg of the other.









0 comments:

Post a Comment

please leave a comment of what do you think about this article.