Posted by **Lwint** on Friday, December 20, 2013 at 8:48am.

ABC is an isosceles triangle. If AB =AC =16, BC=8. D is the midpoint of side AC , and G is the centroid of triangle ABC , find BD .

- Math. Urgent please help -
**Lwint**, Friday, December 20, 2013 at 3:25pm
Anyone please help. I really don't know how to solve this questione

- Math. Urgent please help -
**Reiny**, Friday, December 20, 2013 at 5:35pm
draw the altitude from A to form a right-angled triangle.

Cos C = 4/16 = 1/4

In triangle BCD, by the cosine law ...

BD^2 =8^2 + 8^2 - 2(8)(8)cosC

= 64 +64 - 128(1/4)

= 160

BD = √160 = 4√10

Where does the centroid G enter the picture?

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