Question

Point G is the centroid of the right △ABC with hypotenuse AB=18 in. Find CG.

Answer 1

6 in

Step-by-step explanation:

Let M be the midpoint of AB. ∆CMB and ∆CMA are both isosceles triangles, so CM = (AB)/2 = 9 in.

CG = (2/3)(CM) = (2/3)(9 in)

CG = 6 in

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Comment on centroid and median

The centroid of a triangle is located 1/3 the distance from the midpoint of a side to the opposite vertex. This is true for any median in any triangle. The proof can be developed from the fact that every median divides the triangle's area in half. Here, we just take advantage of this fact.