So we know that = 180 So if we multiply 290 by then we can find its radians in terms of pi (if pi is 180 and you divide 180 by 180 you get one so frankly we multiplying by one so we are not breaking any mathematical rules because if you multiply an number by itself then you get back that number right ?
∴
simplify by dividing the numerator of the first term and denominator of the second term by 10 and then multiplying normally