To investigate a possible relationship between two factors, such as acidity and solubility, you must first identify the variables involved in the experiment. Identify the independent variable, the dependent variable, and any possible confounding variables within this experiment.

Answer the collision of tectonic plates;

To relate to humans in a relational humanly way. 

Ithink the best answer is d increased stability of all other biomes

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.