Question

What is the measure of m? 5 15 E n m = [?]

Answer 1

Answer:  10

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Explanation:

The two smaller triangles are proportional, which lets us set up this equation

5/n = n/15

Cross multiplying leads to

5*15 = n*n

n^2 = 75

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Apply the pythagorean theorem on the smaller triangle on top, or on the right.

a^2+b^2 = c^2

5^2+n^2 = m^2

25+75 = m^2

100 = m^2

m^2 = 100

m = sqrt(100)

m = 10