Answer:
? = 45
Explanation:
Since the triangles are similar, we can use proportions
20 20+8
------- = -------
? ? + 18
20 28
------- = -------
? ? + 18
Using cross products
20 ( ? +18) = = ? * 28
Distribute
20 ? + 360 = 28 ?
Subtract 20 ? from each side
360 = 8?
Divide each side by 8
360/8 = ?
45 = ?