An olympic long jumper leaves the ground at an angle of 23 and traveled a distance of 8.7m before landing. Find the speed at takeoff.

Ok, so i've tried to plug in datas in formulas but i keep getting the wrong answer. The answer is suppose to be 11 m/s. CAn someone guide me in a step by step method to getting the answer? I know i must first find the initial vertical and horizontal speed but i cant arrive at the correct one!

(by the way i'm new in physics)