大、小兩圓重疊,若重疊部分是大圓面積的25%,且是小圓面積的40%。問小圓面積是大圓面積的百分之幾?
2006-10-27 19:30:08 · 3 個解答 · 發問者 ? 1 in 科學 ➔ 數學
設大圓的面積為x
小圓的面積為y
x X 25% = y X 40%
x X 25% ÷ 40% = y
y = x X 62.5%
∴小圓面積是大圓面積的百分之62.5
2006-10-27 20:22:38 · answer #1 · answered by shuk yin 3 · 0⤊ 0⤋
62.5%
2006-10-27 19:35:26 · answer #2 · answered by Anonymous · 0⤊ 0⤋
設大、小兩圓的半徑是 x , y ( x > y )
x^2 (pi) - y^2 (pi) = 25% x = 40% y
25% x = 40% y
0.25x = 0.4y
25x = 40y
40y = 25x
y = 5 / 8 x
y = 62.5%x
Therefore
小圓面積是大圓面積的 62.5%
2006-10-27 19:34:08 · answer #3 · answered by J 7 · 0⤊ 0⤋