X = 16
x = - 16
You could do it this way
x^2 - 256 = 0
(x - 16)(x + 16) = 0
x - 16 = 0
x = 16
x + 16 = 0
x = - 16
(29 m/side)*(2 sides/double)*(3 doubles) = 174 m = 0.174 km
Answer:
22.4
Step-by-step explanation:
using altitude theorem, the height of the triangle is 20
let y = height
10/y = y/40
y² = 400
y = or 20
Now we can us the Pythagorean Theorem to find 'x':
10² + 20² = x²
100 + 400 = x²
x= ≈ 22.4