You can convert (1/625) to an exponent, and it would be ideal to have 5 as the base of it because you want your log base to cancel it out. what i usually do in this case is just test out 5^1, 5^2, etc until i find one that matches the number i need. in this case because the number you're trying to work with is a small fraction, you'll want to use NEGATIVE exponents so it'll create a fraction instead of a large whole number:
See the attached figure to better understand the problem
we know that
tan 29°=AC/CB--------> CB=AC/tan 29° AC=110 ft CB--------> <span>how far the man is from the helicopter landing pad </span>so CB=AC/tan 29°----------> CB=110/ tan 29°----------> CB=198.45 ft
the answer is the man is 198.45 ft from the helicopter landing pad