EXPLANATION
We can apply the Secan Secant Theorem in order to get the value of the side JF as shown as follows:
Replacing terms:
Adding numbers:
Dividing both sides by 40:
Multiplying numbers and simplifying:
As ground to J is the sum of JF + F to ground, we can isolate the measure of the segment JF as shown as follows:
The answer is 60.6 feet