Find the missing length indicated

Answer:
x = 240
Step-by-step explanation:
Using the Altitude- on- Hypotenuse theorem
( leg of big Δ )² = ( part of hypotenuse below it ) × ( whole hypotenuse )
x² = 144 × 400 = 57600 ( take the square root of both sides )
x = [tex]\sqrt{57600}[/tex] = 240