Similar Triangles

Front

What are similar triangles?

Back

Triangles that have the same shape but may differ in size. Their corresponding angles are equal, and their corresponding sides are proportional.

Front

If two triangles are similar, what can be said about their corresponding angles?

Back

The corresponding angles of similar triangles are equal.

Front

If the sides of two similar triangles are in the ratio 2:3, what is the ratio of their areas?

Back

The ratio of their areas is 4:9 (the square of the ratio of their corresponding sides).

Front

What does it mean for sides in similar figures to be proportional?

Back

It means that the lengths of corresponding sides of the figures maintain a constant ratio.

Front

If triangle ABC is similar to triangle DEF, and the length of side AB is 4 cm and side DE is 6 cm, what is the ratio of AB to DE?

Back

The ratio of AB to DE is 4:6 or 2:3.

Front

Are the triangles with sides 3 cm, 4 cm, and 5 cm similar to triangles with sides 6 cm, 8 cm, and 10 cm?

Back

Yes, they are similar because the sides are in the ratio 1:2.

Front

What is the relationship between the perimeters of similar triangles?

Back

The ratio of the perimeters of similar triangles is the same as the ratio of their corresponding sides.

Front

If triangle XYZ is similar to triangle PQR, and the length of side XY is 5 cm and side PQ is 10 cm, what is the scale factor?

Back

The scale factor is 1:2.

Front

True or False: All congruent triangles are similar.

Back

True.

Front

True or False: Similar triangles can have different angles.

Back

False; similar triangles have equal corresponding angles.