我们需要计算三角形的sine值来确定斜坡的倾斜度。

We need to calculate the ___sine of the triangle to determine the slope's steepness.

在直角三角形中，正弦函数等于对边长度除以斜边长度。

In a right triangle, the ___sine of an angle equals the length of the opposite side divided by the hypotenuse.