The correct answer is a,b and c.
a) its core becomes a white dwarf.
b) its outer layers form a nebula , or vast cloud of gas and dust.
c)its outer layers expand , and the star becomes a red giant.

; to find the length of the hypotenuse, you have to use the pythagorean theorem, which states that, in a right triangle,

.

and

would be the two legs, while

would be the hypotenuse. You need to plug in the values of the legs as

and

:

. Solve for the squares of the two numbers, resulting in

, and ultimately

. Find the square root of

and

, and you get

.
Answer:
I think oasis
because wadis is probably a small dry region in a place where there are rains pouring sometimes
I think the answer is periphery, but it could be wrong.
Not defined because of the vertical line.