Answer:
ADC = 100 degrees
Step-by-step explanation:
Please check attachment for diagrammatic representation of the Rhombus
From what we can see in the diagram;
angle CBD and CDB are equal
The reason for this is that we have an isosceles in triangle CBD
CBD = 90- ACB
CBD = 90-40 = 50
We need ADB to completely calculate ADC
CAB is also 40 from the isosceles ABC
That means DBA = 90 - CAB = 90-40 = 50
So from isosceles ABD, we have that ADB is also 50
Mathematically;
ADC = ADB + DBA
ADC = 50 + 50
ADC = 100
