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Pls help

Given: △ABC, CM⊥ AB, BC = 5, AB = 7
CA = 4 sqrt(2)
Find: CM

User Shay Te
by
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1 Answer

3 votes

Answer:

The general plan is to find BM and from that CM. You need 2 equations to do that.

Step One

Set up the two equations.

(7 - BM)^2 + CM^2 = (4*sqrt(2) ) ^ 2 = 32

BM^2 + CM^2 = 5^2 = 25

Step Two

Subtract the two equations.

(7 - BM)^2 + CM^2 = 32

BM^2 + CM^2 = 25

(7 - BM)^2 - BM^2 = 7 (3)

Step three

Expand the left side of the new equation labeled (3)

49 - 14BM + BM^2 - BM^2 = 7

Step 4

Simplify And Solve

49 - 14BM = 7 Subtract 49 from both sides.

-49 - 14BM = 7 - 49

- 14BM = - 42 Divide by - 14

BM = -42 / - 14

BM = 3

Step Five

Find CM

CM^2 + BM^2 = 5^2

CM^2 + 3^2 = 5^2 Subtract 3^2 from both sides.

CM^2 = 25 - 9

CM^2 = 16 Take the square root of both sides.

sqrt(CM^2) = sqrt(16)

CM = 4 < Answer

Explanation:

User Rcorrie
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