在这幅按比例绘制的图纸上，P、Q、R 和 S 是公园里四个花园雕像的位置。 PQRS 是一个四边形。比例尺：1 : 25 000

它不会直接告诉你答案，而是问你卡在哪一步看看 AI 是怎么陪你一步步弄懂这道题的

完整解法

1. Construct the locus of points equidistant from the line segments $PS$ and $PQ$.

Draw the internal angle bisector of $\angle SPQ$ .
Any point on this line is equidistant from the two line segments $PS$ and $PQ$ .

2. Construct the locus of points equidistant from $P$ and $S$, then locate $A$.

Draw the perpendicular bisector of $PS$ .
Any point on this line is equidistant from $P$ and $S$ .

Mark the intersection of this perpendicular bisector with the angle bisector of $\angle SPQ$ as $A$ .

答案

Mark $A$ at the intersection of the internal angle bisector of $\angle SPQ$ and the perpendicular bisector of $PS$ .

1. Convert the actual distance $750\text{ m}$ to centimetres and apply the scale.

Scale $1:25\,000$ means

$1\text{ cm on drawing} = 25\,000\text{ cm in actual distance}$ .

$750\text{ m} = 75\,000\text{ cm}$

So the distance on the scale drawing is

$\frac{75\,000}{25\,000}=3\text{ cm}.$

答案

$HQ = 3\text{ cm}$

1. Construct the two loci that determine the position of $H$.

From $R$ , draw a ray on a bearing of $315^\circ$ .

Using part (b)(i), $HQ = 3\text{ cm}$ , so draw an arc or circle with centre $Q$ and radius $3\text{ cm}$ .

Mark the intersection of this arc with the bearing ray as $H$ .

答案

Mark $H$ at the intersection of the ray from $R$ on a bearing of $315^\circ$ and the circle centred at $Q$ with radius $3\text{ cm}$ .

AI 分析，可能出错

用 AI 批改，圈出写错的那一步，并自动将你的薄弱点存入错题本，形成你的错因库。