warm-up
DESCRIPTION
Warm-Up. If ∆ QRS ∆ ZYX , identify all 3 pairs of congruent angles and all 3 pairs of congruent sides. Geometry 7-2. Similar Polygons. Definition. Figures that are similar (~) have the same shape but not necessarily the same size. Definition. - PowerPoint PPT PresentationTRANSCRIPT
Warm-Up
• If ∆QRS ∆ZYX, identify all 3 pairs of congruent angles and all 3 pairs of congruent sides.
Geometry 7-2
Similar Polygons
Definition
Figures that are similar (~) have the same shape but not necessarily the same size.
Definition• Two polygons are similar polygons if and
only if:– Corresponding angles are congruent– Corresponding side lengths are proportional
ExampleShow that the following triangles are similar.
DefinitionA similarity ratio is the ratio of the lengths of
the corresponding sides of two similar polygons.
The similarity ratio of ∆ABC to ∆DEF is , or .
The similarity ratio of ∆DEF to ∆ABC is , or 2.
Definition
• A similarity statement is a statement that declares two figures similar.
• ∆ABC ~ ∆DEF