某公园计划修建一个菱形花坛,设计图纸上标注了两条对角线的长度分别为6米和8米。施工过程中,工人需要在外围铺设一圈装饰砖,砖块只能沿着花坛边缘铺设。若每块装饰砖长度为0.5米,则至少需要多少块装饰砖才能完整围住花坛?
💡 提示:点击下方 "查看答案" 查看解析,或 "提交答案" 后自动显示结果
本题综合考查平面直角坐标系中的定比分点、两点间距离公式及坐标变换。关键步骤是运用定比分点公式确定C点坐标,再根据方向确定D点坐标,最后分段计算距离并求和。难点在于比例关系的坐标化处理和精确计算带小数的平方根。
🏆
练习完成!
恭喜您完成了本次练习,继续加油提升!
💡 学习建议:您在一元一次方程的应用方面掌握良好,但仍有提升空间。建议重点复习方程求解步骤和实际应用问题。
[{"id":639,"content":"某学生在整理班级同学的课外阅读情况时,绘制了如下条形统计图(描述如下):横轴表示书籍类型(小说、科普、历史、漫画),纵轴表示人数,单位长度为2人。其中小说对应条形高度占3个单位长度,科普占2个单位长度,历史占4个单位长度,漫画占1个单位长度。请问喜欢阅读历史类书籍的学生比喜欢阅读漫画类书籍的学生多多少人?","type":"选择题","subject":"数学","grade":"初一","stage":"初中","difficulty":"简单","answer":"C","explanation":"根据题目描述,纵轴单位长度为2人。历史类条形高度为4个单位长度,因此人数为 4 × 2 = 8 人;漫画类条形高度为1个单位长度,因此人数为 1 × 2 = 2 人。喜欢历史类比漫画类多的人数为 8 - 2 = 6 人。因此正确答案是C。","options":[{"id":"A","content":"2人"},{"id":"B","content":"4人"},{"id":"C","content":"6人"},{"id":"D","content":"8人"}]},{"id":214,"content":"一个长方形的长是8厘米,宽是5厘米,它的周长是_厘米。","type":"填空题","subject":"数学","grade":"初一","stage":"小学","difficulty":"简单","answer":"26","explanation":"长方形的周长计算公式是:周长 = 2 × (长 + 宽)。将长8厘米和宽5厘米代入公式,得到:2 × (8 + 5) = 2 × 13 = 26。因此,这个长方形的周长是26厘米。","options":[]},{"id":2538,"content":"某学生观察一个圆柱形水杯的正视图、俯视图和左视图,发现其正视图和左视图均为矩形,俯视图为一个圆。若该水杯的高为12 cm,底面直径为8 cm,则其正视图的矩形面积为多少?","type":"选择题","subject":"数学","grade":"九年级","stage":"初中","difficulty":"简单","answer":"A","explanation":"题目考查的是投影与视图中的基本几何体三视图知识。圆柱形水杯的正视图是一个矩形,其高度等于圆柱的高(12 cm),宽度等于圆柱底面的直径(8 cm)。因此,正视图的矩形面积为:12 × 8 = 96 cm²。选项A正确。","options":[{"id":"A","content":"96 cm²"},{"id":"B","content":"48 cm²"},{"id":"C","content":"64 cm²"},{"id":"D","content":"32 cm²"}]},{"id":1974,"content":"某学生在操场上竖立了一根高度为2米的旗杆,正午时太阳光线与地面形成的仰角为30°。若此时旗杆在地面上的影长为a米,则a的值最接近以下哪个选项?(已知√3≈1.732)","type":"选择题","subject":"数学","grade":"九年级","stage":"初中","difficulty":"简单","answer":"C","explanation":"本题考查锐角三角函数中正切函数的应用。旗杆垂直于地面,影长与旗杆构成一个直角三角形,其中旗杆为对边,影长为邻边,太阳光线与地面的夹角为30°。根据正切定义:tan(30°) = 对边 \/ 邻边 = 2 \/ a。又因为 tan(30°) = 1\/√3 ≈ 0.577,所以有 2 \/ a = 1\/√3,解得 a = 2√3 ≈ 2 × 1.732 = 3.464。因此,影长a最接近3.46米,正确答案为C。","options":[{"id":"A","content":"1.15"},{"id":"B","content":"2.00"},{"id":"C","content":"3.46"},{"id":"D","content":"4.62"}]},{"id":889,"content":"在某次班级大扫除中,一组学生负责擦窗户。如果每扇窗户需要2分钟擦干净,他们一共用了24分钟完成任务,那么这组学生一共擦了____扇窗户。","type":"填空题","subject":"数学","grade":"初一","stage":"初中","difficulty":"简单","answer":"12","explanation":"题目中给出每扇窗户需要2分钟,总用时24分钟。要求擦了多少扇窗户,可以用总时间除以每扇窗户所需时间:24 ÷ 2 = 12。这是一道简单的一元一次方程应用题,设擦了x扇窗户,则2x = 24,解得x = 12。考查学生将实际问题转化为方程并求解的能力,属于一元一次方程知识点,难度简单。","options":[]},{"id":2265,"content":"在数轴上,点A表示的数是-3,点B与点A的距离为7个单位长度,且点B在原点右侧。若点C是点B关于原点的对称点,则点C表示的数是___。","type":"选择题","subject":"数学","grade":"七年级","stage":"初中","difficulty":"中等","answer":"B","explanation":"点A表示-3,点B与点A的距离为7个单位长度,且点B在原点右侧。因此点B可能在-3的右侧7个单位,即-3 + 7 = 4,所以点B表示4。点C是点B关于原点的对称点,即与4到原点距离相等但方向相反,因此点C表示-4。故正确答案为B。","options":[{"id":"A","content":"4"},{"id":"B","content":"-4"},{"id":"C","content":"10"},{"id":"D","content":"-10"}]},{"id":2760,"content":"某学生在参观博物馆时,看到一件出土于河南安阳的青铜器,器身刻有‘司母戊’三字,形制庄重,纹饰精美。这件文物最有可能属于哪个历史时期?","type":"选择题","subject":"历史","grade":"七年级","stage":"初中","difficulty":"简单","answer":"B","explanation":"司母戊鼎是中国目前已发现的最大、最重的青铜礼器,出土于河南安阳殷墟,而殷墟是商朝后期的都城遗址。‘司母戊’三字表明这是商王为祭祀母亲戊而铸造的青铜器,属于商朝晚期典型器物。夏朝尚未发现成熟青铜铭文,西周青铜器铭文较长且风格不同,春秋时期青铜器风格趋于轻巧,与此鼎特征不符。因此,正确答案为B。","options":[{"id":"A","content":"夏朝"},{"id":"B","content":"商朝"},{"id":"C","content":"西周"},{"id":"D","content":"春秋时期"}]},{"id":251,"content":"某学生在解方程 3(x - 2) + 5 = 2x + 7 时,第一步将等式左边展开得到 3x - 6 + 5,合并同类项后为 3x - 1;第二步将方程写成 3x - 1 = 2x + 7;第三步将 2x 移到左边,-1 移到右边,得到 3x - 2x = 7 + 1;第四步解得 x = ___。","type":"填空题","subject":"数学","grade":"初一","stage":"小学","difficulty":"中等","answer":"8","explanation":"根据题目描述的解方程步骤:第一步展开括号正确,3(x - 2) = 3x - 6,再加5得 3x - 1;第二步方程为 3x - 1 = 2x + 7;第三步移项,将含x的项移到左边,常数项移到右边,即 3x - 2x = 7 + 1;第四步计算得 x = 8。此过程符合解一元一次方程的基本步骤,移项变号规则应用正确,最终结果为8。","options":[]},{"id":2240,"content":"某学生在数轴上从原点出发,先向右移动8个单位长度,再向左移动12个单位长度,接着又向右移动5个单位长度。此时该学生所在位置的数与它到原点的距离之和是___。","type":"填空题","subject":"数学","grade":"七年级","stage":"初中","difficulty":"困难","answer":"2","explanation":"该学生从原点0出发,第一次向右移动8个单位,到达+8;第二次向左移动12个单位,即8 - 12 = -4;第三次向右移动5个单位,即-4 + 5 = +1。因此最终位置是+1。该数到原点的距离是|+1| = 1。题目要求的是‘所在位置的数’与‘到原点的距离’之和,即1 + 1 = 2。本题综合考查正负数在数轴上的表示、有理数加减运算以及绝对值的理解,需分步计算并正确理解‘和’的含义,属于较难层次。","options":[]},{"id":511,"content":"4题","type":"选择题","subject":"数学","grade":"初一","stage":"小学","difficulty":"简单","answer":"待完善","explanation":"解析待完善","options":[]}]