1. **State the problem:** Draw a triangle with a 90° angle and one side measuring 5 centimeters. 2. **Important concepts:** A triangle with a 90° angle is a right triangle. 3. **Steps to draw:** - Draw a horizontal line segment 5 cm long. This will be one leg of the right triangle. - At one endpoint of this segment, draw a vertical line perpendicular to the first segment. - Connect the endpoint of the vertical line to the other endpoint of the horizontal segment to form the hypotenuse. 4. **Explanation:** The 90° angle is formed where the horizontal and vertical segments meet. 5. **Summary:** The triangle has one leg 5 cm long and a right angle between the legs. Final answer: A right triangle with one leg 5 cm and a 90° angle at the vertex where the legs meet.