From the question it is given that, The ratio between an exterior angle and the interior angle of a regular polygon is 1: 5
Let us assume exterior angle be y And interior angle be 5y
We know that, sum of interior and exterior angle is equal to 180∘,
y+5y=180∘6y=180∘y=180∘/6y=30∘
the measure of each interior angle =5y=5×30∘=150∘