Last year, the school library had a total of x books. over the summer, the library acquired another 42 books and now has a total of 2,402 books. which equation could be used to find x, the number of books the library had last year?

a.2,402 + x = 42
b. x + 42 = 2,402
c.42x = 2,402
d. x - 42 = 2,402

Prove the converse of the pythagorean theorem using similar triangles. the converse of the pythagorean theorem states that when the sum of the squares of the lengths of the legs of the triangle equals the squares length of the hypotenuse, the triangle is a right triangle. be sure to create and name the appropriate geometric figures.