This is a vector problem.

A man starts at home and runs 5 miles north and then 5 miles in a direction 23 degrees south of west. Now he wants to go back home in a straight line. How far does he need to go and in what direction?
so i found that the hypotenuse equals 5.4 miles but i cannot find the angle because it is not a right triangle.

To solve this vector problem, let's break it down into smaller steps:

Step 1: Analyze the first leg of the journey.
The man runs 5 miles north, which we can represent as a vector in the positive y-direction. Therefore, we can write this vector as (0, 5).

Step 2: Analyze the second leg of the journey.
The man runs 5 miles in a direction 23 degrees south of west. To calculate this vector, we need to find its components.
The horizontal component can be found by multiplying the magnitude (5 miles) by the cosine of the angle (23 degrees south of west) since cosine gives us the adjacent side length.
The vertical component can be found by multiplying the magnitude (5 miles) by the sine of the angle (23 degrees south of west) since sine gives us the opposite side length.
Let's calculate the components:

Horizontal component = 5 miles * cos(23°) = 4.444 miles (rounded to 3 decimal places)
Vertical component = 5 miles * sin(23°) = -2.118 miles (rounded to 3 decimal places)

Since the man is moving south, the vertical component is negative.

Now we can write this vector as (-4.444, -2.118) since the horizontal component is West (-4.444 miles) and the vertical component is South (-2.118 miles).

Step 3: Add the vectors to find the resultant vector.
To find the resultant vector (the total displacement), we need to add the two vectors together. We add the horizontal and vertical components separately:

Resultant horizontal component = 0 + (-4.444) = -4.444 miles
Resultant vertical component = 5 + (-2.118) = 2.882 miles

So the resultant vector can be written as (-4.444, 2.882) miles.

Step 4: Calculate the distance and direction of the return journey.
To find the distance and direction of the return journey, we can use the Pythagorean theorem and trigonometry.

The distance (hypotenuse) can be found using the Pythagorean theorem:
Distance = sqrt((-4.444)^2 + 2.882^2) = 5.39 miles (rounded to 2 decimal places)

The angle can be found by taking the arctangent of (2.882 / -4.444) since the vertical component is positive and the horizontal component is negative in the final resultant vector:
Angle = atan(2.882 / -4.444) = -30.65 degrees (rounded to 2 decimal places)

Thus, the man needs to go approximately 5.39 miles at an angle of -30.65 degrees (south of west) to return home in a straight line.