Question

I need help on this???

Answer 1

Another way to do this is to apply pythagoras 3 times, since there are 3 right triangles. Assuming the sides not named here are a and b, you get:

a^2 + b^2 = 16^2
9^2 + y^2 = a^2
y^2 + 7^2 = b^2

You can solve these to y=3√7

Answer 2

Use the geometric mean for right triangles here. Like this
`(9)/(y)= (y)/(7)`. Cross multiply to get
`y^(2)=63`, and
`y= √(63)`. That simplifies down to
`y= √(9*7)`. Pull out the 9 as a perfect square of 3 and you're left with
`y=3 √(7)`, first choice above.