عنوان مقاله [English]
نویسنده [English]چکیده [English]
The solar altitude angle is one of the factors that affect the amount of energy received by the surface of the earth from the sun, which by turn depends on the latitude, degree of the earth's slopes, direction of the earth's slopes, the time of the day and the season of the year. There are many formulas for the estimation of solar altitude angle in the slopes. Here I attempt to consider these factors, using one of the experimental formulas, daily mean of the solar altitude angle consider during the year in the slopes of 0 to 90 degrees, in 16 major and minor directions and in Iran's latitude (from 25 to 40 North degrees). To estimate the relationship between the amounts of the slopes angle with the solar altitude angle we can use calculated digits. We can draw several conclusions from these relationships, including determining the slopes of the surface of the earth, in which the solar altitude angle has the most or the least tendency.