Hachie Chapter 7 Flashcards
Properties of Proportions
a/b = c/d is equivalent to
1) ad = bc 2) b/a = d/c
3) a/c = b/d 4) (a+b)/b = (c+d)/d
Cross-Product Property
The product of the extremes is equal to the product of the means.
Side-Angle-Side Similarity (SAS~) Theorem
If an angle of one triangle is congruent to an angle of a second triangle, and the sides including the two angles are proportional, then the triangles are similar.
Angle-Angle Similarity (AA~) Theorem
If two angles of one triangle are congruent to tow angles of another triangle, then the triangles are similar.
Side-Side-Side Similarity (SSS~) Theorem
If the corresponding sides of two triangles are proportional, then the triangles are similar
The altitude to the hypotenuse of a right triangle
divides the triangle into two triangles that are similar to the original triangle and to each other
The length of the altitude to the hypotenuse of a right triangle
is the geometric mean of the lengths of the segments of the hypotenuse.
The altitude to the hypotenuse of a right triangle separates the hypotenuse so that
the length of each leg of the triangle is the geometric mean of the length of the adjacent hypotenuse segment and the length of the hypotenuse.
Side-Splitter Theorem
If a line is parallel to one side of a triangle and intersects the other two sides, then it divides those sides proportionally.
Corollary to the Side-Splitter Theorem
If three parallel lines intersect two transversals, then the segments intercepted on the transversals are proportional.
Triangle-Angle-Bisector Theorem
If a ray bisects an angle of a triangle, then it divides the opposite side into two segments that are proportional to the other two sides of the triangle.