Answer:
O = 41 degrees
Step-by-step explanation:
the sum of all angles in a triangle is always 180 degrees.
the graphic shows that this triangle has 2 equal sides. that means that both angles at O and at M are equal.
so, we know all three angles and can calculate
7y + 2×(4y - 15) = 180
7y + 8y - 30 = 180
15y = 210
y = 14
so, the angle at O is
O = 4×14 -15 = 56 - 15 = 41 degrees
