已知半径426米,弧高8米,求弧长多少米?
问题描述:
已知半径426米,弧高8米,求弧长多少米?
答
cosα=(426-8)÷426=0.98122065727699530516431924882629
α=11.1214°
2α=22.2418°
弧长:2πR×α÷360=2×3.1415926×426×22.2418÷360=165.370452016≈=165.37米