Answer:
A central angle has the same measure as its arc.
Explanation:
We have been given a statement and we are supposed to fill in the given blank.
Statement: A angle has the same measure as its arc.
Since we know that in a circle the measure of inscribed angle is half the measure of its subtended arc and the measure of central angle equals to the measure of its subtended arc.
Therefore, the missing word from our given statement is "central".