There are two triangles, a big triangle and a small triangle that is inside the big triangle. Because the base of the triangles are parallel to each other( indicated by the arrow), and the small triangle is perfectly inside the bigger triangle, the sides of the triangles are proportional.
It is know that the base of the small triangle is 3.5, and the hypotenuse of the small triangle is 7cm. it is also known that the the hypotenuse of the big triangle is (7+8)=15 and the base of the big triangle is unknown.
Since the triangles are proportional, to find the base of the big triangle
