4. A pyramid has a base that is a right triangle. The base of the right triangle is 3 units. The height of the right triangle is 12 units. The height of the pyramid is 14 units.
Which expression represents the volume of the pyramid?

Could someone with number 1 and 2

What is the total surface area of this square pyramid?

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.