For this case we have that by definition, the Pythagorean theorem states that:
![c = \sqrt {a ^ 2 + b ^ 2}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/o89x3k0kvonx350e3d1nq6kqxbco2ncd3e.png)
Where:
c: It is the hypotenuse of the triangle
a, b: Are the legs
According to the figure, the hypotenuse is represented by BC, then:
![BC = \sqrt {12 ^ 2 + 16 ^ 2}\\BC = \sqrt {144 + 256}\\BC = \sqrt {400}\\BC = 20](https://img.qammunity.org/2020/formulas/mathematics/middle-school/61wfx5k19omojfulb4gat3ql8dbm2xq48k.png)
Thus, the hypotenuse of the triangle is 20
ANswer:
Option D