How do you find the surface arra or volume of each rectangular prism​

In δabc, if the length of side b is 3 centimeters and the measures of ∠b and ∠c are 45° and 60°, respectively, what is the length of side c to two decimal places?

Select the margin of error that corresponds to the sample mean that corresponds to each population: a population mean of 360, a standard deviation of 4, and a margin of error of 2.5%

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?