HEL Items 19–20. Neil Armstrong was the first person to walk on the moon. If a person was the first to walk on the moon, then that person was Neil Armstrong.19.If a person Neil Armstrong, then that person the first person to walk on the moon.20.Since Neil Armstrong was the first person to walk on the moon, the contrapositive is . Since the contrapositive is ,
the must be true.

9.4.34  question   to estimate the height of a stone  figure, an observer holds a small square up to her eyes and walks backward from the figure. she stops when the bottom of the figure aligns with the bottom edge of the  square, and when the top of the figure aligns with the top edge of the square. her eye level is 1.811.81 m from the ground. she is 3.703.70 m from the figure. what is the height of the figure to the nearest hundredth of a  meter?