Answer:
110in
Step-by-step explanation:
You are given the angle and the length of one leg of the triangle. Therefore, you will want to use one of the trigonometric formulae you've learnt. The available ones are:
where <em>O</em> represents the leg opposite the angle, <em>A </em>represents the leg Adjacent to the angle, and <em>H</em> represents the hypotenuse. The lamppost in this problem is the leg <em>opposite the angle</em>, so you want a formula that has <em>O </em>in the equation, namely <em>sin </em>or <em>tan</em>. Because you were given the leg <em>adjacent </em>to the angle, it makes sense here to use <em>tan.</em> Set up the equation as such to solve:
For some reason, it wanted you to convert 70 degrees to radians, so that may have been where you could have run into issues. If you plugged in 70 as degrees, you would get 48 which isn't an option. Converting 70 to 1.22 rad gets you the answer of 110 in.