Help solve 4 and 5 please

Step-by-step explanation:

4). a). If the diagonals of a parallelogram are congruent, then it must be a RECTANGLE.

b). If the diagonals of a parallelogram are perpendicular, then it must be a SQUARE.

c). If the diagonals of a parallelogram bisect the angles of the parallelogram, then it must be a RHOMBUS.

d). If the diagonals of a parallelogram are perpendicular and congruent, then it must be a SQUARE.

e). If a parallelogram has four congruent sides, then it must be a SQUARE.

5). Given quadrilateral SELF is a rhombus.

a). All sides of a rhombus are equal,

   Therefore, ES = EL = 25

b). Diagonals of a rhombus bisects the opposite angles,

   Therefore, m∠ELS = m∠FLS

    3x - 2 = 2x + 7

    3x - 2x = 7 + 2

    x = 9

c). Diagonals of the rhombus bisect the opposite angles, and adjacent angles are supplementary.

m∠ELF = 2(m∠ELS) = 2(2y - 9)

m∠LES = 2(m∠LEF) = 2(3y + 9)

And 2(2y - 9) + 2(3y + 9) = 180

(2y - 9) + (3y + 9) = 90

5y = 90

y = 18  

explanation:

step-by-step explanation: