去年七月初,我校高一级数学学年考试有这样一道应用题:如图1,用一把米尺和一个计算器(可由三角函数值求角),如何测算堤对地面的倾斜角α? In early July of last year, the high school mathematics year exam in our school had such an application: As shown in Figure 1, using a meter ruler and a calculator (calculating the angle by the trigonometric function value), how to measure the inclination angle α of the bank to the ground?