Question

Dora

請問這個要怎麼算

Answer 1

✨ 最佳解答 ✨

Ny-Ålesund

假設半徑 = r，OM = x、ON = 2x，則
OA^2 = OM^2 + AM^2 = r^2
OC^2 = ON^2 + CN^2 = r^2
=> OM^2 + AM^2 = ON^2 + CN^2 = r^2
x^2 + 9^2 = (2x)^2 + 6^2
x^2 + 81 = 4x^2 + 36
3x^2 = 45, x^2 = 15, x = √15 = OM (數字好像有點怪，應該沒算錯吧?)

r^2 = 15 + 81 = 96 => 圓面積 = 96π