Answer:
12.6
Explanation:
The two left sides have lengths, so this allows you to establish the ratio of the lengths of the sides of the triangles,
left triangle : right triangle
ratio = 25 : 17.5
The bottom sides are also in the same ratio.
ratio = 18 : w
Write a proportion by setting the ratios equal and solve for w.
25/17.5 = 18/w
Cross multiply.
25w = 17.5 * 18
25w = 315
w = 12.6
Answer: 12.6