Question

the 3 - 4 - 5 rule is used to lay out an angle of how many degrees? 30 60 90 120

Explanation:

The 3 - 4 - 5 rule is based on the Pythagorean theorem \(a^{2}+b^{2}=c^{2}\). For \(a = 3\), \(b = 4\), \(c=5\), we have \(3^{2}+4^{2}=9 + 16=25=5^{2}\). A triangle with side lengths in the ratio \(3:4:5\) is a right - triangle. By the definition of a right - triangle, the angle between the sides of lengths \(3\) and \(4\) is \(90^{\circ}\).

Answer:

90