(b) Find the measure of ZABC to the nearest degree.

Answer:
The diagonals are AC = 16 and DB = 30
We must determine the rhombus altitude
altitude = AC * DB / (2 * side)
altitude = 16 * 30 / (2 * 17)
altitude = 14.1176470588235
arc sine (angle D) = opp/hyp = 14.1176470588235 / 17
arc sine (angle D) = 0.83044982698962
angle D = 56.145 degrees
In a rhombus, Angle D = Angle B so Angle B = 56.145
In a rhombus, the diagonals bisect the angles so
Angle ABC = 56.145 / 2 = 28.0725 Degrees
Source: https://www.1728.org/quadrhom.htm
Step-by-step explanation: