Answer:
7
Step-by-step explanation:
Thing about centroids is they create segments that are spilt with one piece [tex]\frac{1}{3}[/tex] and the larger piece [tex]\frac{2}{3}[/tex] .
So, if the whole segment is 21, then the large piece is [tex]\frac{2}{3}[/tex] of 21. The small piece is [tex]\frac{1}{3}[/tex] of 21.
TE = 21 · [tex]\frac{1}{3}[/tex] = [tex]\frac{21}{3}[/tex] = 7
