what is the value of x in the diagram below?

Answer:
C
Step-by-step explanation:
using the Altitude- on- Hypotenuse theorem
(leg of big Δ )² = (part of hypotenuse below it ) × ( whole hypotenuse )
x² = 20 × (20 + 36) = 20 × 56 = 1120 ( take square root of both sides )
x = [tex]\sqrt{1120}[/tex] = [tex]\sqrt{16(70)}[/tex] = [tex]\sqrt{16}[/tex] × [tex]\sqrt{70}[/tex] = 4[tex]\sqrt{70}[/tex]