Use pythagorean theoram(idk the spelling). Basically a^2+b^=c^2 where a and b are the legs of the triangle and c is the hypotenuse. so if we solve it we get 6^2 + (7/4)^2 = c^2
since the jogger wants to complete the trail in 30 minutes and the total length of the trail is 3528m you just need to divide the length of the trail (3528) by the total amount of time to get the answer
You are expected to memorize the general shape of the sine function, including where the peaks and zero crossings are. The graph shows you the value of sin(270°) = -1
