Really urgent! i have 5 minutes remaining! which figure is a chord of 0f?

Evaluate the expression for the given value of the variable 2×(c2-5) for c=4

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?

Three times the sum of a number and seven is negative thirty-six. what is the number?