The interior angles of any triangle must add up to 180° in measure. Right angles have measure 90°, so the missing angles in both triangles here have measure 45°.
In a 45°-45°-90° triangle, the legs and hypotenuse occur in a ratio of 1 : √2. This means
(1) x = 48 √2
(2) 88 = √2 x → x = 88 / √2 = 44 √2
You could also set up trigonometric equations to solve for x in each case:
The interior angles of any triangle must add up to 180° in measure. Right angles have measure 90°, so the missing angles in both triangles here have measure 45°.
In a 45°-45°-90° triangle, the legs and hypotenuse occur in a ratio of 1 : √2. This means
Because a proportional relationship is one where x is proportional (equal) to y, and Graph A does not fall into that category, and Graph B does, the answer should be B.