Since the line is a tangent, that means the PT and OP are perpendicular (they make a right angle) Sooo, the triangle is a right triangle. Use Pythagorean Theorem to calculate or Pythagorean Triples for a shortcut (5, 12, 13)
Vertical line is removed then horizontal. Its goes blue, red, blue. A vertical line is to be removed and the colour is red. That leaves B as the answer.
notice that the triangle ADH, since the segment AL is an angle bisector, meaning it cuts the angle A in two equal halves, then the triangle ADH is only using half of A.
