Answer:
NF = 25
Step-by-step explanation:
Since ∆NKF ~ ∆LZF, the ratio of their corresponding side lengths would also be the same.
This means that:
KF/ZF = NF/LF
KF = x + 3
ZF = 4
NF = 15 + x + 3 = x + 18
LF = x + 3
Plug in the values into the equation
(x + 3)/4 = (x + 18)/(x + 3)
Cross multiply
(x + 3)(x + 3) = (x + 18)(4)
x² + 3x + 3x + 9 = 4x + 72
x² + 6x + 9 = 4x + 72
x² + 6x + 9 - 4x - 72 = 0
x² + 2x - 63 = 0
Factorize to find x
x² + 9x - 7x - 63 = 0
x(x + 9) -7(x + 9) = 0
(x + 9)(x - 7) = 0
x + 9 = 0 or x - 7 = 0
x = -9 or x = 7
We'd use the positive value of x, which is 7.
Therefore, x = 7.
✅NF = 15 + (x + 3)
Plug in the value of x
NF = 15 + (7 + 3) = 15 + 10
NF = 25
