def calculate_area(width, height)
  raise TypeError, "Width must be a number" unless width.is_a?(Numeric)
  raise TypeError, "Height must be a number" unless height.is_a?(Numeric)

  raise ArgumentError, "Width must be positive" unless width > 0
  raise ArgumentError, "Height must be positive" unless height > 0

  width * height
end

# Usage:
calculate_area(10, 20) # works fine
calculate_area(-5, 10) # raises ArgumentError