Find the domain and range of relation

Which basic geometric term has no width, no length, and no thickness? line b. point c. angle d. plane

Use sigma notation to represent the following series for 9 terms.

The statements below can be used to prove that the triangles are similar. ? △abc ~ △xyz by the sss similarity theorem. which mathematical statement is missing? ∠b ≅ ∠y ∠b ≅ ∠z