Yes, the square root of 2 (√2) is considered a complex number. A complex number is of the form a + bi, where a and b are real numbers, and i is the imaginary unit (√-1). In the case of √2, it can be expressed as √2 + 0i, where the real part a is √2 and the imaginary part bi is 0. Since √2 can be represented in the form of a complex number, it is included in the set of complex numbers (ℂ). However, it is also a real number since the imaginary part is zero (b = 0). All real numbers can be considered as complex numbers with a zero imaginary part.