I’ve got a couple trigonometry questions that I really need help on. I don’t understand them at all.

5. the work done by a force is given by the expression W=Fd cos theta, where F is the magnitude of the force, d is the distance traveled, and theta is the angle of the applied force to the direction of motion. Calculate the amount of work down by a 5 an force acting at a 75 -degree angle to move a box 30 m
(answer choices shows below)

7. the stand on a camera can be tilted to a maximum of 15 degrees above the horizontal. if a photographer wants to take a picture of the top of a 90 ft building with the camera on the ground, how far back must he place the camera? use a half angle identity to choose the expression that best finds the distance
(answer choices below)

please help I don’t understand these