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30 votes
30 votes
Find the exact length of side a.​

Find the exact length of side a.​-example-1
User ExohJosh
by
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1 Answer

6 votes
6 votes

Answer:

Explanation:

I think the best way to do this is to find B using the cos law. The two other angles are equal

b = 3sqrt(3)

a = 3

c = 3

b^2 = a^2 + b^2 - 2ab*cos(B)

(3sqrt(3)^2 = 3^2 + 3^2 - 2*3*3 * cos(B)

27 = 9 + 9 - 18*cos(B)

27 = 18 - 18*cos(B)

9 = - 18*cos(B)

9/-18 = cos(B)

-1/2 = cos(B)

B = cos-1(-1/2)

B = 120

<A + <C + 120 = 180

<A = <C

2A + 120 = 180

2A = 60

A = 30

The question says angle A so that's what I did.

User Bahadir Tasdemir
by
2.8k points