The distribution of earthquakes defines the boundary of which major earth feature?

The distribution of earthquakes outlines the boundaries of the earth's tectonic plates. The crust is broken up into slabs of rock called tectonic plates. There are seven major plates and many smaller ones. The boundaries of these plates, where they interact with each other is marked by earthquake activity. The plates diverge, converge or slide past each other at slow rates. The movement of the plates generates earthquakes. 

The answer is b im not sure 

In a right-angled triangle: 1- the hypotenuse is the longest side2- we can apply pythagorean rule which states that: (hypotenuse)^2 = (side1)^2 + (side2)^2for the given triangle,longest side is 15 cm  side1 = 9 cmside2 is 12 cm  to check whether the triangle is right-angled or not,compare (15)^2 to the summation of (9)^2 and (12)^in other words, compare 225 to the summation of 81 and 144if they are both equal, then the triangle is right-angles, otherwise, it is not.you haven't provided the diagram showing her work, so i cannot tell the choice. however, apply my explanation to the question you have.