When it comes to the roof of buildings, then by the word"Slope" means the angle of inclination of the roof shell to the horizon. In geodesy, this parameter is an indication of the slope steepness, and in the design documentation this is the degree of deviation of direct elements from the baselines. The gradient in degrees does not cause anybody's questions, but the percentage bias causes confusion sometimes. It's time to deal with this unit of measurement in order to clearly understand what it is and, if necessary, easily transfer it to other units, for example, to the same degrees.
Calculation of the slope in percent
Try to imagine a right-angled triangleABC, lying on one of its legs AB. The second leg of the aircraft will be directed vertically upwards, and the hypotenuse of the AU forms an angle with the lower leg. Now we have a little to remember trigonometry and calculate its tangent, which will just characterize the slope formed by the hypotenuse of the triangle with the lower leg. Suppose that the catheter AB = 100 mm, and the altitude BC = 36.4 mm. Then the tangent of our angle will be 0.364, which corresponds to 20 ° according to the tables. What, then, will the slope be in percent? To translate this value into these units, we just multiply the tangent by 100 and get 36.4%.
How to understand the slope angle in percent?
If the traffic sign shows 12%, then thismeans that on every kilometer of such an ascent or descent the road will rise (fall) by 120 meters. To convert a percentage value to degrees, you simply need to calculate the arctangent of this value and, if necessary, translate it from the radians into the familiar degrees. The same goes for construction drawings. If, for example, it is indicated that the slope angle in percent is 1, then this means that the ratio of one leg to the other is 0.01.
Why not in degrees?
Many people are probably interested in the question:"Why for the bias to use some more interest?" Indeed, why not just do one degree. The fact is that for any measurements there is always some error. If the design documentation will apply degrees, then inevitably there will be difficulties with the installation. Take at least the same sewer pipe. Accuracy of several degrees with a length of 4-5 meters can lead it completely to the other from the desired side position. Therefore, in the instructions, recommendations and project documentation, interest is usually applied.
Application in practice
Suppose that the project to build a suburbanat home involves the construction of a pitched roof. It is required to check its slope in percent and degrees if it is known that the height of the ridge is 3.45 meters, and the width of the future dwelling is 10 meters. Since the front of the roof is an equilateral triangle, it can be divided into two rectangular triangles, in which the height of the ridge will be one of the legs. The second leg is found dividing the width of the house in half.
