Find the vertex of f(x)=x^2-10x+21

Your answer would be ahere is how: perimeter is how long all the sides are. in a rectangle, there are two sets of parallel sides. so, to find this, we would to the following.(15x2)+(4x2)30+838if you have questions ask! and mark me brainliest! i really wanna level up : 3

Need the graph to answer this.