Answer:

Explanation:
this is a right triangle, and we are given the hypotenuse as 11 and one side as 4. we are to find AC.
recall for right triangles, we can use the Pythagorean theorem, which states that 
 , where a and b are the shorter sides and c is the hypotenuse.
, where a and b are the shorter sides and c is the hypotenuse.
so, we substitute the values: 
 . then, expand and simplify.
. then, expand and simplify.

finally, take the square root of both sides.
 . ignore the negative answer since length can't be negative.
. ignore the negative answer since length can't be negative.