Simultaneous Equation question

Find the height of a square pyramid that has the volume of 32 ft.³ and a base lengthof 4 feet

1. what is the measure of ∠abc? what is the measure of ∠abd?

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?