Write SQL query to solve given problem: Calculate the average age of the male patients that have hypertension.. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT SUM(CASE WHEN T2.deathdate IS NULL THEN ROUND((strftime('%J', date('now')) - strftime('%J', T2.birthdate)) / 365) ELSE ROUND((strftime('%J', T2.deathdate) - strftime('%J', T2.birthdate)) / 365) END) / COUNT(T2.patient) FROM conditions AS T1 INNER JOIN patients AS T2 ON T1.PATIENT = T2.patient WHERE T1.DESCRIPTION = 'Hypertension' AND T2.gender = 'M'