Write the Word or Phrase That Best Completes Each Statement $a ^ { 2 } + 2 a b + b ^ { 2 }$

Short Answer

Write the word or phrase that best completes each statement or answers the question.
Provide the missing information.
-The trinomial $a ^ { 2 } + 2 a b + b ^ { 2 }$ is a square trinomial. Its factored form is .