I'm pretty sure you can use the pythagorean theorem to find the hypotenuse length. One side of the triangle is 2.4 and the other side is 3.7 (because7.4 divided by 2 since the line is cut in half) so, a² + b² = c², or 2.4² + 3.7² = x² and that simplified is 5.76 + 13.69 or 19.45. This means that x² = 19.45 so find the sqaure root of each side to get x by itself: x = approximately 4.4 in. Hope this helps!