Cumulative Practice Problems

4) All circles are similar because they all lack angle measurements. Like triangles have angle measurements, and squares and other shapes. Except circles. That's one thing that makes them all similar.

All circles are similar BECAUSE the ratio of the circumference to the diameter is ALWAYS the same for all circles, that is: Circumference / Diameter = Pi

Problem 3

They are similar because   the missing angle in the first triangle is 180 - 123 - 36  = 21°

So....two  angles of  triangle CDE  = two angles of triangle CAB

So....by  Angle-Angle congruency, the triangles are similar