Unit 13
Maju Minda
Mari ulang kaji Ruang: sudut dan segi tiga, garis selari dan serenjang, perimeter, luas dan isi padu.
Jawab setiap soalan. Jika salah, baca petunjuk dan cuba lagi.
整章复习 = ulang kaji bab
这一单元把“空间”这一章的重点再练一次：认识角和三角形，分辨平行线和垂直线，求周长、面积和体积，再解决应用题。每一题先想清楚要找的是哪一种量，用哪一个公式，单位要写什么。
例子：边长 3 cm 的正方形，周长 12 cm，面积 9 cm²；边长 3 cm 的正方体，体积 27 cm³。
注意：周长 cm、面积 cm²、体积 cm³，单位不能混。
chapter review = ulang kaji bab
Here you go over the key ideas of the Space chapter once more: angles and triangles, parallel and perpendicular lines, perimeter, area, volume and word problems. For each question, decide which quantity you need, which formula to use and which unit to write.
Example: a square with 3 cm sides has a perimeter of 12 cm and an area of 9 cm²; a cube with 3 cm sides has a volume of 27 cm³.
Watch out: perimeter in cm, area in cm², volume in cm³; never mix the units.
Segi tiga
Namakan segi tiga ini.
命名三角形 = namakan segi tiga
给三角形命名时，先看角：有没有一个角画着小正方形记号？那个记号表示直角。再看边：边上的红色小线条表示一样长。有直角的三角形，就用直角来命名。
例子：一个三角形三条边都画了一条红线，三边相等，叫等边三角形。
注意：没有等长记号的边，不能凭感觉说它们一样长。
naming a triangle = namakan segi tiga
To name a triangle, look at the angles first: is there a small square mark at a corner? That mark means a right angle. Then look at the sides: small red strokes mean equal lengths. A triangle with a right angle is named after that angle.
Example: a triangle with one red stroke on each of its three sides has three equal sides and is called equilateral.
Watch out: do not assume sides are equal unless they carry the same mark.
Segi tiga
Namakan segi tiga ini.
看等长记号 = lihat tanda sisi sama
边上画了相同记号的边一样长。数一数：三条边都有记号、只有两条边有记号、还是都没有记号？三种情况的三角形名字不一样。
例子：一个三角形三条边各画一条红线，三边都等长，是等边三角形。
注意：底边和两条斜边看起来差不多长，也要以记号为准。
look at the equal-side marks = lihat tanda sisi sama
Sides with the same mark are equal in length. Count: do all three sides have marks, only two, or none? Each case gives the triangle a different name.
Example: a triangle with one red stroke on each of its three sides has three equal sides and is equilateral.
Watch out: even if the base looks about as long as the slanting sides, trust the marks.
Sudut
Sudut yang bertanda jingga ialah …
角的种类 = jenis sudut
拿一张长方形卡片的角当作直角来比较：比卡片的角小（比较尖）的是锐角，刚好吻合的是直角，比卡片的角大（张得比较开）的是钝角。把卡片的角对准橙色记号的顶点来比。
例子：时钟两点整，两根针之间的角比卡片的角小。
注意：角的大小看两条边张开多少，不看边画得多长。
kinds of angles = jenis sudut
Use the corner of a rectangular card as a right angle: an angle smaller than the corner (sharper) is acute, one that fits exactly is right, and one that opens wider is obtuse. Put the card's corner on the vertex with the orange mark.
Example: at two o'clock the angle between the clock hands is smaller than the card's corner.
Watch out: the size of an angle depends on how wide the arms open, not on how long they are drawn.
Garis
Dua garis ini ialah …
两条线的关系 = hubungan dua garis
先问：两条线会不会相交？永远不相交、距离处处一样的是平行线。如果相交，再看交点：有直角记号（成九十度）的是垂直线；相交但不成直角的，两种都不是。线斜着摆，也一样可以用这个方法判断。
例子：门框的直边和地面相交成直角。
注意：不要因为线是斜的，就以为不能成直角。
how two lines are related = hubungan dua garis
First ask whether the lines meet. Lines that never meet and stay the same distance apart are parallel. If they meet, look at the crossing: a right-angle mark (90°) means perpendicular; meeting at any other angle means neither. Slanted lines are judged the same way.
Example: the upright edge of a door frame meets the floor at a right angle.
Watch out: slanted lines can still meet at a right angle.
Garis
Dua garis ini ialah …
看距离是否相等 = adakah jaraknya sama
两条线在图里没有碰到，不代表它们永远不相交。用尺量一量左边两条线之间的距离，再量右边的距离：如果距离不一样，把线画长一点，它们迟早会相交。
例子：火车的两条铁轨，不管在哪里量，距离都一样。
注意：判断时不能只看图里有没有相交，要比较两端的距离。
is the gap the same = adakah jaraknya sama
Two lines that do not touch in the picture may still meet later. Measure the gap between them at the left end and at the right end with a ruler: if the gaps differ, the lines will meet when extended.
Example: the two rails of a railway track are the same distance apart wherever you measure.
Watch out: do not just check whether they touch inside the picture; compare the gaps at both ends.
Perimeter
Berapakah perimeter segi empat tepat ini?
长方形的周长 = perimeter segi empat tepat
周长是绕图形一圈的总长度。长方形有两条长边、两条宽边，可以四条边相加，也可以先把长和宽相加，再乘二，单位是厘米。
例子：长 9 cm、宽 2 cm 的长方形，周长 = 9 + 2 + 9 + 2 = 22 cm。
注意：长乘宽是面积；只加一次长和宽只有半圈。
perimeter of a rectangle = perimeter segi empat tepat
Perimeter is the total distance around a shape. A rectangle has two lengths and two widths: add all four sides, or add the length and width and double it, in centimetres.
Example: a 9 cm by 2 cm rectangle has a perimeter of 9 + 2 + 9 + 2 = 22 cm.
Watch out: length × width is the area, and length + width once is only half the way round.
Luas
Sebuah petak semaian berbentuk segi empat sama bersisi 12 m. Berapakah luasnya?
正方形的面积 = luas segi empat sama
正方形的长和宽都等于边长，面积 = 边长 × 边长，单位是平方米。两位数乘两位数，可以用竖式或者拆开来算。
例子：边长 11 m 的正方形，面积 = 11 × 11 = 121 m²。
注意：边长乘四是周长，不是面积。
area of a square = luas segi empat sama
The length and width of a square both equal the side, so area = side × side, in square metres. For a two-digit times two-digit product, use a column method or split the numbers.
Example: a square with 11 m sides has an area of 11 × 11 = 121 m².
Watch out: the side times 4 is the perimeter, not the area.
Luas
Berapakah luas segi tiga ini?
高在三角形外 = tinggi di luar segi tiga
这个三角形的顶点在底边外面，高是从顶点垂直落到底边延长线上的虚线。底只算三角形本身的那一段，不算延长出来的虚线。再用二分之一乘底乘高。
例子：底 6 cm、高在外面 7 cm，面积 = ½ × 6 × 7 = 21 cm²。
注意：底乘高以后要取一半；底和高相加没有意义。
height outside the triangle = tinggi di luar segi tiga
The top corner of this triangle is beyond the end of its base, so the height is the dashed line dropped straight onto the extended base. The base is only the triangle's own side, not the dashed extension. Then use ½ × base × height.
Example: base 6 cm with an outside height of 7 cm gives ½ × 6 × 7 = 21 cm².
Watch out: halve the product of base and height; adding them makes no sense.
Isi padu
Sebuah kotak barang kemas berbentuk kubus bersisi 7 cm. Berapakah isi padunya?
正方体体积 = isi padu kubus
正方体每条边一样长，体积 = 边长 × 边长 × 边长。先算前两个相乘，再把结果乘边长，单位是立方厘米。
例子：边长 9 cm 的正方体，9 × 9 = 81，81 × 9 = 729 cm³。
注意：只把两个边长相乘，得到的是一个面的面积。
volume of a cube = isi padu kubus
All edges of a cube are equal, so volume = side × side × side. Multiply the first two, then multiply the result by the side again, in cubic centimetres.
Example: a cube with 9 cm sides: 9 × 9 = 81 and 81 × 9 = 729 cm³.
Watch out: multiplying the side by itself only once gives the area of one face.
Isi padu
Berapakah isi padu kuboid ini?
长方体体积 = isi padu kuboid
体积 = 长 × 宽 × 高。图上标了三个长度，三个都要用到；平方米乘米得立方米。
例子：6 m × 4 m × 2 m 的长方体，体积 = 48 m³。
注意：长乘宽只是底面积；三个数相加不是体积。
volume of a cuboid = isi padu kuboid
Volume = length × width × height. The picture labels three lengths and all three are needed; square metres times metres give cubic metres.
Example: a 6 m × 4 m × 2 m cuboid has a volume of 48 m³.
Watch out: length × width is only the base area, and adding the three numbers is not the volume.
Isi padu
Permukaan yang berlorek mempunyai luas 45 m². Tentukan isi padu bongkah ini.
涂色面 × 垂直边 = luas berlorek × sisi serenjang
涂色的那一面面积已经给出，等于两条边相乘；只要再乘上和这一面垂直、往后伸的边，就得到体积，单位是立方米。
例子：涂色面 20 m²，往后 3 m，体积 = 60 m³。
注意：答案要用体积单位。
shaded face × perpendicular edge = luas berlorek × sisi serenjang
The area of the shaded face is given; it is already two edges multiplied. Multiply it by the edge going back at right angles to the face to get the volume in cubic metres.
Example: a shaded face of 20 m² and 3 m going back give 60 m³.
Watch out: the answer needs a volume unit.
Selesaikan masalah
Luas sebuah taman bunga segi empat tepat ialah 96 m². Lebarnya 8 m. Berapakah panjang pagar di sekeliling taman itu?
先求长再求周长 = cari panjang, kemudian perimeter
题目给的是面积和宽，问的是篱笆（周长）。第一步：面积 ÷ 宽 = 长。第二步：周长 = 二乘长加宽。两步都要做完。
例子：面积 54 m²、宽 6 m → 长 9 m → 周长 = 2 × (9 + 6) = 30 m。
注意：只求出长还不是题目要的答案；面积加宽也不是周长。
length first, then perimeter = cari panjang, kemudian perimeter
The question gives the area and the width but asks for the fence, which is the perimeter. Step 1: area ÷ width = length. Step 2: perimeter = 2 × (length + width). Finish both steps.
Example: area 54 m² and width 6 m → length 9 m → perimeter 2 × (9 + 6) = 30 m.
Watch out: the length alone is not what is asked, and area plus width is not the perimeter.
Selesaikan masalah
Sebuah bekas kubus bersisi 6 cm penuh dengan air. Semua air itu dituang ke dalam bekas kuboid bertapak 9 cm × 8 cm. Berapakah tinggi air dalam bekas kuboid?
倒水求水高 = tuang air, cari tinggi
水从一个容器倒进另一个容器，水的体积不会变。先算正方体容器里水的体积（边长连乘三次），再算长方体容器的底面积（长乘宽），用体积除以底面积，就是水的高度。
例子：80 cm³ 的水倒进底面积 20 cm² 的盒子，水高 = 80 ÷ 20 = 4 cm。
注意：要除以底面积，不是只除以其中一条边。
pouring water to find its height = tuang air, cari tinggi
When water is poured into another container, its volume stays the same. Find the volume of water in the cube (the side three times), then the base area of the cuboid (length × width), and divide the volume by the base area to get the water height.
Example: 80 cm³ of water in a box with a 20 cm² base stands 80 ÷ 20 = 4 cm high.
Watch out: divide by the base area, not by just one edge.
Ringkasan
Syabas!
Ruang
Sudut, segi tiga, garis selari dan serenjang, perimeter (cm), luas (cm²) dan isi padu (cm³).
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