19.Marvin is working on a problem for his geometry class. He has to determine if quadrilateral ABCD is a parallelogram, and if so, what kind.

He determines that the diagonals of the quadrilateral have the following characteristics:

- the slopes are opposite reciprocals

- the diagonals have the same midpoint

- the diagonals are congruent

- the diagonals are perpendicular

How would you classify the shape?

square

Rhombus

Rectangle

Kite

Step-by-step explanation:

The parallelogram that has those characteristics is the square.

The square is perfectly symmetric, both diagonals are congruent, because all sides of the square are congruent. Also, the diagonals bisects each angle of the square, creating triangles. Those triangles have 45° angles at their base and the third-angle is 90°, that is, it's a right triangle, where that right angle is between diagonals.

Therefore, a square has congruent and perpendicular diagonals, they have the same midpoint, and their slopes are opposite reciprocals of each other because that's the definition of perpendicularity.

Therefore, the right answer is square.

1 is b and 2 is d

step-by-step explanation:

the entire expression should be subtracted from 30. to subtract the quantity, distribute the negative sign, which changes the signs on the terms. so, the –2 changes to positive and gets added to 30 instead of subtracted from it.

hope this ! ^w^