一个直径是9米的圆形喷水池周围有一条环形小路,路宽一米,这条小路的面积是多
\u4e00\u4e2a\u76f4\u5f8410m\u7684\u55b7\u6c34\u6c60,\u5468\u56f4\u6709\u4e00\u6761\u73af\u5f62\u5c0f\u8defi,\u8def\u5bbd3m,\u8fd9\u6761\u5c0f\u8def\u7684\u9762\u79ef\u662f\u591a\u5c11\u76f4\u5f8410\u7c73\uff0c\u90a3\u4e48\u534a\u5f84\u5c31\u662f5\u7c73\u3002
(5+3)\u00d7\uff085+3\uff09\u00d73.14 -5\u00d75\u00d73.14
=200.96 - 78.5
=122.46\uff08\u5e73\u65b9\u7c73\uff09
3.14X(20/2+1)²-3.14X(20/2)²=65.94
5×5×3.14-4.5×4.5×3.14=14.9绛旓細鍐呭渾鍗婂緞=10梅2=5绫 澶栧渾鍗婂緞=5+2=7绫 姘存偿璺潰绉 =澶栧渾闈㈢Н-鍐呭渾闈㈢Н =3.14脳7²-3.14脳5²=75.36骞虫柟绫 ~涓鍒绘案杩523涓轰綘瑙ｇ瓟锛岀浣犲涔犺繘姝~~濡傛灉浣犺鍙垜鐨勫洖绛旓紝璇峰強鏃剁偣鍑汇愰噰绾充负婊℃剰鍥炵瓟銆戞寜閽畘~鎵嬫満鎻愰棶鑰呭湪瀹㈡埛绔彸涓婅璇勪环鐐光滄弧鎰忊濆嵆鍙倊浣犵殑閲囩撼鏄垜鍓嶈繘...
绛旓細锛5*5-4*4锛*3.14=28.26锛岄摵楣呭嵉鐭崇殑闈㈢Н鏄28.26m²
绛旓細姘存睜鍗婂緞4绫筹紝鍒欑幆褰㈠皬璺崐寰5绫筹紝闈㈢Н=3.14 * 5^2-3.14 *4^2 =3.14*25-3.14*16 =3.14*9 =28.26
绛旓細涓涓渾褰㈠柗姘存睜锛鐩村緞闀垮叚绫筹紝鍦ㄥ畠鐨鍛ㄥ洿鏈変竴鏉″涓绫崇殑鐜舰灏忚矾锛屽皬璺殑闈㈢Н鏄灏戝钩鏂圭背锛熸濊矾锛鍦嗗舰姘存睜澶栭潰鍔犲皬璺紝閭ｅ皬璺氨鏄竴涓渾鐜紝鍦嗙幆闈㈢Н灏辨槸澶у渾鍑忓皬鍦嗐傚垪寮忥細灏忓渾鍗婂緞锛6/2=3绫 澶у渾鍗婂緞锛3+1=4绫 闈㈢Н锛歋=3.14脳(4*4-3*3)=21.98骞虫柟绫炽
绛旓細鐩村緞11绫炽傛爮鏉嗗叏闀3.14x11
绛旓細鑰冭檻涓や釜鍦嗙殑闈㈢Н宸嵆鍙 灏忓渾鍗婂緞涓4锛岄潰绉负16蟺 澶у渾鐨勫崐寰勬瘮灏忓渾澶1锛屽崐寰勪负5锛岄潰绉负25蟺 灏忚矾鐨勯潰绉氨鏄25蟺-16蟺=9蟺鈥︹﹁繕涓嶆竻妤氱殑璇濓紝HI鎴戝晩鈥︹
绛旓細涓涓洿寰10绫崇殑鍦嗗舰鍠锋按姹锛屽崰鍦伴潰绉槸锛78.5骞虫柟绫筹級锛屽畠鐨勫懆闀夸负31.4绫
绛旓細姘存睜鍗婂緞锛8/2=4绫 澶у崐寰勶細4+1=5绫 灏忚矾闈㈢Н锛3.14x(5x5-4x4)=28.26骞虫柟绫
绛旓細鍙傝冪瓟妗堬細鍠锋按姹闈㈢Н锛3*3*3.14=28.26 鎬婚潰绉細4*4*3.14=50.24 姘存偿闈㈢Н锛50.24-28.26=21.98 鏈涢噰绾硚~
绛旓細鍠锋按姹犳槸鍦嗗舰鐨勶紝鐩村緞5绫筹紝澶栧洿鍔犱竴鍦堝皬璺紝鐩稿綋浜庢墿澶т簡杩欎釜鍦嗗舰锛屽皬璺1绫锛岃鏄庤繖涓渾鐨勭洿寰勬墿澶т簡2绫炽傚皬璺潰绉氨鍙互鐢ㄦ墿澶т箣鍚鐨勫渾鐨勯潰绉噺鍘诲師鏉鍦嗗舰鍠锋按姹鐨勯潰绉傚ぇ鍦鐩村緞涓7绫筹紝鍒欏崐寰勪负3.5绫筹紝鍠锋按姹犵洿寰勪负5绫筹紝鍒欏崐寰勪负2.5绫筹紝灏忚矾闈㈢Н搴斾负3.5²蟺-2.5²蟺=6蟺鈮18....
