A team of archaeologists wants to dig for fossils in a triangular area marked by three stakes. The distances between the stakes are shown in the diagram. Which expression represents the dig area in square feet?

the first one, all those points on the line just make a strait line.

correct answer:

b.(19,-2)

step-by-step explanation:

this can be solved first with pythagorean theorem, which tells us to square both legs of the triangle and sum it. this will be equal to the square of the hypotenuse.

the hypotenuse is the side "opposite" the 90 degree angle, which is x.

so we can write using pythagorean theorem,

simplifying:

to further simplify this radical, we need to use the property  

thus