根号3≈1.732 根号2≈1.414&
来源:学生作业帮 编辑:搜搜做题作业网作业帮 分类:数学作业 时间:2024/07/28 18:59:09
![](http://img.wesiedu.com/upload/d/23/d23bde02202d0f19cb3fe561bc9c80af.jpg)
![根号3≈1.732 根号2≈1.414&](/uploads/image/z/15170787-27-7.jpg?t=%26nbsp%3B%E6%A0%B9%E5%8F%B73%E2%89%881.732%26nbsp%3B+%26nbsp%3B+%26nbsp%3B+%26nbsp%3B+%26nbsp%3B+%E6%A0%B9%E5%8F%B72%E2%89%881.414%26)
∵BC=20 ∠BAC=45-30=15 ∠ABC=45
∴AC=BC*Sin45/Sin15=20*0.707/0.258=54.8
∴AD=√3/2*AC=0.866*54.8=47.457>45
安全,可以通行.
∴AC=BC*Sin45/Sin15=20*0.707/0.258=54.8
∴AD=√3/2*AC=0.866*54.8=47.457>45
安全,可以通行.