Help visualizing a trigonometry problem?

A receiver starts his route on the right hash mark of the forty yard line. He runs down the field at a fifty degree angle toward the right sideline and at the thirty yard line he turns back toward the middle of the field and catches the ball on the right hash mark of the fifteen yard line.

How far did the receiver actually run to make the reception at the fifteen yard line?

I know how to do trig perfectly so I don t really need help with the math. I just cannot figure out the triangle being made. If someone could help me visualize the lengths of the sides of the triangle being made that would be very helpful!

ted s2015-08-28T15:59:43Z

let A be start , B be the point on 30 yd line where he turns , C be the ending point...
|AC| = 25 , angle A has measure 40° , so 10 / |AB| = cos 40° ;
let D be the point on AC which is at the 30 yd line , |BD| / 10 = tan 40° ;
|BC|² = 15² + |BD|²...distance is |BC| + |AB|

Sqdancefan2015-08-28T16:22:03Z

My guess is that the angle is measured from the downfield direction. See diagram. The triangle is an obtuse triangle.
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