Perimeter

数方格求周长 = kira unit 每一小格的边长是一个单位。沿着绿色图形的外边走一圈：上边五格、右边两格、下边五格、左边两格，把四段加起来，就是周长。只数外面的边，图形里面的格线不算。 例子：一个三格长、一格宽的长方形，周长是 3 + 1 + 3 + 1 = 8 个单位。 注意：数的是边的长度，不是格子的数目。

counting units = kira unit Each small square has sides of one unit. Walk round the outside of the green shape: five along the top, two down the right, five along the bottom and two up the left. Add the four parts to get the perimeter. Only the outside edges count, not the grid lines inside. Example: a rectangle three squares long and one square wide has perimeter 3 + 1 + 3 + 1 = 8 units. Watch out: count the lengths of the edges, not the number of squares.

正多边形的周长 = perimeter poligon sekata 正多边形每条边一样长，边上都有同样的红色记号。与其一条一条加，不如用乘法：边数乘一条边的长度。正六边形有六条边，每条二十五厘米，所以六乘二十五。 例子：一个正方形相框每边 30 cm，周长是 4 × 30 = 120 cm。 注意：先数清楚有几条边，再乘。

perimeter of a regular polygon = perimeter poligon sekata All sides of a regular polygon are equal and carry the same red mark. Instead of adding them one by one, multiply: the number of sides times the length of one side. A regular hexagon has six sides of twenty-five centimetres each, so work out six times twenty-five. Example: a square photo frame with 30 cm sides has perimeter 4 × 30 = 120 cm. Watch out: count the sides carefully before multiplying.

三角形的周长 = perimeter segi tiga 等边三角形三条边都有同样的记号，只标出一条边的长度就够了，周长是三乘边长：三乘九等于二十七厘米。等腰三角形有两条边带记号，表示它们一样长；没有标长度的那条带记号的边，长度和另一条带记号的边相同，所以是十加十加四，等于二十四厘米。 例子：等腰三角形两腰各 7 cm、底 5 cm，周长 7 + 7 + 5 = 19 cm。 注意：没写长度的边，要看记号找出它的长度，不能漏加。

perimeter of triangles = perimeter segi tiga All three sides of the equilateral triangle carry the same mark, so one labelled length is enough: the perimeter is three times the side, 3 × 9 = 27 cm. In the isosceles triangle two sides carry marks, meaning they are equal; the marked side without a label has the same length as the labelled one, so the perimeter is 10 + 10 + 4 = 24 cm. Example: an isosceles triangle with equal sides of 7 cm and a base of 5 cm has perimeter 7 + 7 + 5 = 19 cm. Watch out: use the marks to find any side without a label, and do not leave it out.

直角三角形的周长 = perimeter segi tiga bersudut tegak 直角三角形三条边长度不一样，只能把三条边一一相加。数字比较大的时候，可以列竖式：个位对齐，五加零加五等于十，写零进一；十位一加二加二，再加进上来的一，等于六。 例子：边长 6 cm、8 cm、10 cm 的直角三角形，周长 6 + 8 + 10 = 24 cm。 注意：直角的小方块不是边，不用加。

perimeter of a right-angled triangle = perimeter segi tiga bersudut tegak The three sides of this right-angled triangle are all different, so add them one by one. With bigger numbers, use the column method: line up the ones, 5 + 0 + 5 = 10, write 0 and carry 1; tens 1 + 2 + 2 + the carried 1 = 6. Example: a right-angled triangle with sides 6 cm, 8 cm and 10 cm has perimeter 6 + 8 + 10 = 24 cm. Watch out: the small right-angle square is not a side and is not added.

长方形的周长 = perimeter segi empat tepat 长方形两条长边一样长，两条宽边也一样长，所以只标出一条长和一条宽。周长要把四条边都加上：十四加六加十四加六，等于四十米。也可以先算一条长加一条宽等于二十，再乘二。 例子：一块 8 m 长、3 m 宽的地，周长 8 + 3 + 8 + 3 = 22 m。 注意：只加一长一宽只得到周长的一半。

perimeter of a rectangle = perimeter segi empat tepat A rectangle's two long sides are equal and its two short sides are equal, so only one length and one width are labelled. The perimeter adds all four sides: 14 + 6 + 14 + 6 = 40 m. You can also add one length and one width to get 20, then double it. Example: a plot 8 m long and 3 m wide has perimeter 8 + 3 + 8 + 3 = 22 m. Watch out: adding just one length and one width gives only half the perimeter.

求长方形周长 = cari perimeter segi empat tepat 图上只写出一条长和一条宽，但长方形有四条边：对边一样长。把四条边全部加起来，或者先加一长一宽，再乘二。 例子：长 9 cm、宽 4 cm 的长方形，周长 9 + 4 + 9 + 4 = 26 cm。 注意：图上没有写长度的边，也要算进去。

perimeter of a rectangle = cari perimeter segi empat tepat The picture labels only one length and one width, but a rectangle has four sides, with opposite sides equal. Add all four, or add one length and one width and then double. Example: a rectangle 9 cm by 4 cm has perimeter 9 + 4 + 9 + 4 = 26 cm. Watch out: sides without a written length must be included too.

等腰三角形的周长 = perimeter segi tiga sama kaki 图上只写了两个长度，但三角形有三条边。看红色记号：带同样记号的两条边一样长，所以没写长度的那条边可以从另一条找到。然后把三条边都加起来。 例子：两条带记号的边各 6 cm、底 9 cm，周长 6 + 6 + 9 = 21 cm。 注意：每一条边都要用上，而且只用一次。

perimeter of an isosceles triangle = perimeter segi tiga sama kaki Only two lengths are written, but a triangle has three sides. Look at the red marks: the two sides with the same mark are equal, so the unlabelled one can be found from the other. Then add all three sides. Example: two marked sides of 6 cm each and a base of 9 cm give 6 + 6 + 9 = 21 cm. Watch out: use every side, and use each side only once.