Please help, no spam answers please, I will mark brainleist!

D.

Step-by-step explanation:

Its given that the rectangle has a perimeter of 60 units. A rectangle has four sides, and to get the perimeter, you add up all four sides. You are given one side is 20 units, and the other as 'x.'

So,

x + x + 20 + 20 = 60

2x + 40 = 60

Example for *wrong*

Letter C, x + 20 = 60, that would'nt equal 60 because youre only adding two sides instead of all four.

Hopefully this helps :)

last option

step-by-step explanation:

given that δdef is right and isoceles,

assuming that side df is the hypotenuse means that de an ef are the other 2 sides that intersect at 90° and are of equal length.

because they are of equal length, we can say that they are congruent

because they intersect at 90°, their slopes must be opposite reciprocals.

only the last option satisfies these conditions.

i am sure it will be 90 degrees.

step-by-step explanation: