Use the figure below for questions 9 - 9. If \( D F=61 \) and \( E F=18 \), find \( D E \).

To determine \( D E \) given that \( D F = 61 \) and \( E F = 18 \), we'll assume that points \( D \), \( E \), and \( F \) are collinear (lying on a straight line). Here's how to approach the problem: 1. **Understand the Positions:** - If \( D \), \( E \), and \( F \) are on a straight line, and \( D \) is at one end, \( F \) is at the other end, and \( E \) is somewhere in between, then: \[ D F = D E + E F \] 2. **Plug in the Known Values:** - Given \( D F = 61 \) and \( E F = 18 \): \[ 61 = D E + 18 \] 3. **Solve for \( D E \):** \[ D E = 61 - 18 = 43 \] **Answer:** \( D E = 43 \)