We will have the following:
*First: From properties of the rhombus the following is true:


*Second: We know that the sum of all internal angles of a quadrilateral add 360°, so the following is true:

So:

This, since from properties of the rhombus m<3 = m<4, now we wil have:


Now, we will have the following:


And finally, we can see that the measurement of angle 5 is:
