Question

I just need the length of the unknown side and why it makes sense

Answer 1

Explanation:

According to Pythagorean theorem, the square value of hypotenuse (the side length that sees angle measure 90) is equal to sum of square value of two legs:

let x represent the missing length

x^2 + 3^2 = 7^2

x^2 + 9 = 49 subtract 9 from both sides

x^2 = 40 find the root for both sides

x =
`√(40)` or 6.3 inches approximately