What potential pitfalls should programmers be aware of when using the arccos function in PHP for angle calculations?

When using the arccos function in PHP for angle calculations, programmers should be aware that the function returns the angle in radians, not degrees. To convert the result to degrees, programmers need to multiply the result by 180 and divide by pi.

// Calculate the angle in degrees using arccos function
$angle_radians = acos($value);
$angle_degrees = $angle_radians * 180 / pi();

echo "Angle in degrees: " . $angle_degrees;