congruency and similarity Flashcards
perpendicular bisector
- draw 2 arcs from one end point of the line with the radius more than half of the line.
- draw 2 arcs from the other end point of the line with the radius more than half of the line.
- draw a line segment from the two point of intersections of the arcs.
angle bisector
- draw an arc on the two lines forming the angle.
- draw an arc in between the two lines from the two arcs on the lines forming the angle.
- draw a line segment between the point of intersection of the two arcs between the lines forming the angle and the angle itself
SSS test for congruency
3 given lengths of the sides of a triangle
SAS test for congruency
2 given lengths of the sides of a triangle and an INCLUDED angle
AAS test for congruency
2 INCLUDED angles and 1 given length of the sides of a triangle
RHS test for congruency
1 INCLUDED angle, hypotenuse and 1 given length of the sides of a triangle
AA test for similarity
2 INCLUDED angles
SSS test for similarity
ratio of corresponding sides should be the same
SAS test for similarity
1 INCLUDED angle and ratio of corresponding sides should be the same
ratio of areas of similar triangles
a1/ a2 = (l1/ l2)2
ratio of volume of similar triangles
v1/ v2 = (l1/ l2)3
ratio of area of triangles with common height
1/2 x b1 x h/ 1/2 x b2/ h = b1/ b2
ratio of area of triangles with common base
1/2 x b x h1/ 1/2 x b x h2 = h1/ h2