Answer:
OB = 8
OC = 8
OA = 8
AC = 16
BD = 16
OD = 8
Explanation:
Given, rectangle ABCD, with diagonals AC and BD, and OC = 3x – 4, OB = x + 4,
thus, since diagonals of a rectangle are equal, therefore, AC = BD.
Invariably, 2*OC = 2*OB
Thus,

Solve for x

Add 8 to both sides


Subtract 2x from both sides


Divide both sides by 4


OB = x + 4 = 4 + 4 = 8
OC = 3x - 4 = 3(4) - 4 = 12 - 4 = 8
OA = OC = 8
AC = 2*OC = 2*8 = 16
BD = 2*OB = 2*8 = 16
OD = OB = 8