Question

Please help me with this

Answer 1

Answer:

AB = 2*sqrt(5) or

AB = 4.47

Step-by-step explanation:

AB is the hypotenuse of a right triangle A and B and the corner where 2 and 4 meet.

The length of AB is governed by the Pythagorean Theorem.

AB^2 = x^2 + y^2                  Substitute 2 and 4 for x and y    

AB^2 = 2^2 + 4^2                 Expand the right side

AB^2 = 4 + 16                        Add the right side

AB^2 = 20                             Take the square root of both sides

sqrt(AB^2) = sqrt(20)

Factor 20 = 2*2 *5

Rule: when taking the square root of a number the pairs can take 1 member of the pair outside the root sign and throw the other one a way.

AB = 2 * sqrt(5)                       One of the roots has been thrown away.