Similar triangles and Parts

Front

What is a midsegment in a triangle?

Back

A midsegment is a line segment that connects the midpoints of two sides of a triangle. It is parallel to the third side and its length is half the length of that side.

Front

What does it mean for triangles to be similar?

Back

Triangles are similar if they have the same shape, which means their corresponding angles are equal and their corresponding sides are in proportion.

Front

How do you find the scale factor between two similar triangles?

Back

The scale factor is found by dividing the length of a side of one triangle by the length of the corresponding side of the other triangle.

Front

What is the AA (Angle-Angle) similarity postulate?

Back

The AA postulate states that if two angles of one triangle are equal to two angles of another triangle, then the triangles are similar.

Front

What is the SAS (Side-Angle-Side) similarity postulate?

Back

The SAS postulate states that if two sides of one triangle are in proportion to two sides of another triangle and the included angles are equal, then the triangles are similar.

Front

What is the SSS (Side-Side-Side) similarity postulate?

Back

The SSS postulate states that if the corresponding sides of two triangles are in proportion, then the triangles are similar.

Front

If triangle PQR is similar to triangle DEF, and the length of side PQ is 6 and side DE is 9, what is the scale factor from triangle PQR to triangle DEF?

Back

The scale factor is 1.5 (9/6).

Front

If two triangles have one angle of 60 degrees and the other angles are 30 degrees and 90 degrees, are they similar?

Back

Yes, they are similar by the AA postulate.

Front

What is the relationship between the lengths of the sides of similar triangles?

Back

The lengths of the corresponding sides of similar triangles are proportional.

Front

How can you determine if two triangles are not similar?

Back

If the corresponding angles are not equal or the sides are not in proportion, the triangles are not similar.