SIMILARITY: A REVIEW A REVIEW Moody Mathematics
Midsegment: a segment that joins the midpoints of 2 sides of a triangle? Moody Mathematics
A Midsegment is parallel to one side of the triangle and half of its length. Moody Mathematics
x 16 Find x, the length of the midsegment X = 8 Moody Mathematics
8 midsegments x y 7 20 Find x, y, z z Moody Mathematics
8 midsegments x y 7 20 x=8, y=10, z=14 x=8, y=10, z=14 z Moody Mathematics
Property of Proportions #1 Moody Mathematics
Property of Proportions #2 Moody Mathematics
Property of Proportions #3 Moody Mathematics
Property of Proportions #4 Moody Mathematics
Property of Proportions #5 Moody Mathematics
PRACTICE:
Definition: Polygons are similar if: 1. Corresponding Angles are congruent 2. Corresponding sides are in proportion Moody Mathematics
x 12 y w Find w, x, y, z in these similar trapezoids z Moody Mathematics
x 12 y w z Moody Mathematics
x 12 y w W=60 o z X=9.375 Y=9.6 Z=120 o Moody Mathematics
Similar Triangles Moody Mathematics
AA Postulate: If 2 angles of one triangle are congruent to 2 angles of another triangle, then the 2 triangles are similar. Moody Mathematics
SSS~ Postulate: If all 3 sides of two triangles are in proportion, then the triangles are similar. Moody Mathematics
SAS~ Postulate: If 2 sides of two triangles are in proportion and their included angles are congruent, the triangles are similar. Moody Mathematics
PRACTICE:
Similar? Yes by SAS~ Yes by SAS~ Moody Mathematics
Similar? Yes by SSS~ Moody Mathematics
Similar? Yes by AA Moody Mathematics
62 o 48 o 50 o Similar? No! Corresponding angles are not congruent. No! Corresponding angles are not congruent. 68 o 70 o Moody Mathematics
8 4 7 x Find x Moody Mathematics
4 6 9 Find x x Moody Mathematics