The image of the diagram is missing, so i have attached it.
Answer:
a = 30°
Step-by-step explanation:
From the diagram attached, we can see that the 2 angles a and 5a are interior supplementary angles.
The sum of interior supplementary angles is 180°
Thus;
5a + a = 180
6a = 180
a = 180/6
a = 30°
