Help ASAP ill give brainliest

Thales was an ancient philosopher familiar with similar triangles. one story about him says that he found the height of a pyramid by measuring its shadow and his own shadow at the same time. if the person is 5-ft tall, what is the height of the pyramid in the drawing?

Which of the following is the shape of a cross section of the figure shown below

What are the exclude value of mn+3m