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按边命名 = namakan ikut sisi 三角形可以按边来命名，也可以按角来命名。先读清楚题目给了哪些资料：说到边，就想“几条边一样长”；说到角，就想“有没有直角”。再从选项里找最合适的名字。 例子：一个三角形三边都是 5 cm，按边命名就是等边三角形。 注意：命名前先读清楚题目给的是边的资料还是角的资料。

naming by sides = namakan ikut sisi A triangle can be named by its sides or by its angles. First read what information the question gives: for sides, ask how many sides are equal; for angles, ask whether there is a right angle. Then pick the most suitable name. Example: a triangle whose three sides are all 5 cm is named equilateral by its sides. Watch out: before naming, check whether the question tells you about the sides or the angles.

长方形里的垂直边 = sisi serenjang dalam segi empat tepat 两条线互相垂直，就是相交成直角。在图上找出边 AB，看它的两个端点：在哪个顶点有直角记号、另一条边从那里和 AB 相交，那条边就和 AB 垂直。 例子：直角三角形 KLM 中，直角在 L，所以 KL 和 LM 互相垂直。 注意：垂直的两条边一定在某个顶点相交。

perpendicular sides in a rectangle = sisi serenjang dalam segi empat tepat Two lines are perpendicular when they meet at a right angle. Find side AB in the picture and look at its two ends: a side that meets AB at a corner with a right-angle mark is perpendicular to AB. Example: in right-angled triangle KLM with the right angle at L, sides KL and LM are perpendicular. Watch out: perpendicular sides always meet at a corner.

长方形切成两个三角形 = segi empat tepat dipotong dua 沿对角线剪开长方形，得到两个一样大的三角形，每个是长方形面积的一半。先算长方形的面积（长乘宽），再除以二。 例子：14 cm × 5 cm 的纸，面积 70 cm²，剪开后每个三角形 35 cm²。 注意：题目问的是一个三角形，不是整张卡。

a rectangle cut into two triangles = segi empat tepat dipotong dua Cutting a rectangle along its diagonal gives two equal triangles, each half of the rectangle. Find the rectangle's area (length × width), then halve it. Example: a 14 cm × 5 cm paper has an area of 70 cm², so each triangle is 35 cm². Watch out: the question asks about one triangle, not the whole card.

用掉以后剩多少 = baki selepas digunakan 水箱装满时，水的体积就是水箱的体积（长乘宽乘高）。用掉一部分，就用减法：总体积减去用掉的，得到剩下的，单位是立方米。 例子：5 m × 2 m × 1 m 的水箱装满，用掉 4 m³，剩下 10 − 4 = 6 m³。 注意：用掉的要减，不是加。

how much is left = baki selepas digunakan When the tank is full, the volume of water equals the tank's volume (length × width × height). Some is used, so subtract: total minus the amount used gives what is left, in cubic metres. Example: a full 5 m × 2 m × 1 m tank with 4 m³ used has 10 − 4 = 6 m³ left. Watch out: subtract the water used; do not add it.