Answer:
The size of the angle formed at the top of the sail is 35.
Step-by-step explanation:
We know that the sum of all angles inside a triangle must be 180. This is a rule.
So we know that a right triangle is called like that because one angle is a 90-degree angle.
Then we have that:
180 = right angle + lower edge angle + angle top of the sail
180 = 90 + 55 + angle top of the sail
Solving for 'angle top of the sail' we have:
angle top of the sail = 180 - 90 - 55 = 35
The size of the angle formed at the top of the sail is 35.