From the figure, we can conclude that the little triangle is an isosceles triangle, the greatest angle is 90 because ∠A = 90 and they are supplementary, therefore, using the triangle sum theorem:
90% of the milkshakes had whipped cream because 90/100 as a percentage is 90%
Answer
215 can only be divided by 5
The circumference of a circle of radius
is

So, in your case, the circumference is

The circumference is actually the length of the "perimeter", so the answer to questions 1 and 2 looks the same actually
The point where the lines intersect is the point that satisfies both equations.
It is (1, 5), selection C.