At the beginning of the lesson it says "a medida" = "the measurement'. Then at the end it asks to translate "a medida". Definitions offered are "measurement" or "measure" . I put measurement and got it wrong.
Just to clarify, although your answer should be accepted: in English, measurement can mean both (A) the act of measuring and (B) the result of the measuring. In Portuguese, there are two different words for that: "medição" (A) and "medida" (B). As for measure, when used as a noun, it's translated as "medida", but when used as a verb, it's translated as "medir" (since all Portuguese verbs end in either "ar", "er", or "ir"). =)