To find the length of the cable, we can use the Pythagorean theorem. The problem gives us a right triangle where:
- The height of the pole creates one leg of the triangle (20 ft).
- The distance from the base of the pole to the anchor point on the ground creates the other leg of the triangle (10 ft).
- The cable itself is the hypotenuse of the triangle.
Let's denote the length of the cable as \( c \). According to the Pythagorean theorem:
\[ c^2 = \text{(height)}^2 + \text{(distance from the pole)}^2 \]
Substituting the values:
\[ c^2 = (20)^2 + (10)^2 \] \[ c^2 = 400 + 100 \] \[ c^2 = 500 \] \[ c = \sqrt{500} \approx 22.36 \]
Rounding this to the nearest tenth, we get:
\[ c \approx 22.4 \text{ ft} \]
So, the length of the cable is approximately 22.4 ft.