bentangan = net Cut a 3D shape along some edges and lay it flat on the table; the flat pattern is called a net. A net lets us see every face at once. Example: an opened box shows top and bottom, front and back, and two sides, 2 + 2 + 2 = 6 faces. Watch out: the faces of a net stay joined; loose cut-out pieces are not a net.
Langkah 2
Semak bilangan bentuk asas
Kubus: 6 segi empat sama. Kuboid: 6 segi empat tepat, atau 4 segi empat tepat dan 2 segi empat sama. Silinder: 1 segi empat tepat dan 2 bulatan. Piramid: 4 segi tiga dan 1 segi empat sama. Kon: 1 bulatan dan 1 bahagian melengkung.
bilangan bentuk asas = 基本形状的数目 检查展开图时，数一数有几个面、各是什么形状，要和立体图形完全一样。例如圆柱的展开图要有 2 个圆和 1 个长方形。 例子：四角锥的展开图要有 1 个正方形和 4 个三角形，共 1 + 4 = 5 块。 注意：少了一个面，折起来就会有一个洞。
bilangan bentuk asas = number of basic shapes When checking a net, count its faces and name each shape; they must match the 3D shape exactly. A cylinder net, for instance, needs 2 circles and 1 rectangle. Example: a square pyramid net needs 1 square and 4 triangles, 1 + 4 = 5 pieces. Watch out: if one face is missing, the folded shape will have a hole.
Langkah 3
Bayangkan lipatan
Bayangkan setiap bahagian dilipat pada sisinya tanpa bertindih atau meninggalkan ruang.
bayangkan lipatan = imagine the folds Looking at a net, picture each part folding up along its edge and check that everything closes neatly, with no faces overlapping and no gaps left. Example: a cross-shaped cube net has 1 middle square as the base, 4 squares folding up around it, and 1 as the lid, 1 + 4 + 1 = 6 squares. Watch out: 6 squares in one straight row can never fold into a cube.
Aktiviti interaktif
Lipat bentangan
Pilih satu bentangan, tekan Lipat untuk melihat bentuk 3D, kemudian tekan Buka.
bentangan = net Opening a 3D shape and laying it flat gives its net; folding the net along its edges makes the 3D shape again. Example: a cube net has 6 squares, and a cylinder net has 1 rectangle with 2 circles at the top and bottom. Watch out: when folded, faces must not overlap or leave gaps.
Semak cepat · Soalan 1 / 2
Cuba sendiri
Pilih jawapan. Jika belum tepat, baca petunjuk dan cuba lagi.
maksud bentangan = meaning of a net The question asks what is done to a 3D shape to make a net. Recall the three arrow steps in Langkah 1. Check by asking whether the result is flat or solid. Example: a box with 6 faces still has 6 faces as a net, 6 - 0 = 6, so the number of faces stays the same. Watch out: a net is a picture-like pattern, so think about how it looks lying on a table.
Semak cepat · Soalan 2 / 2
Cuba sendiri
Pilih jawapan. Jika belum tepat, baca petunjuk dan cuba lagi.
bentangan kubus = net of a cube The question asks what a cube net must contain. Count how many faces a cube has, then think about the shape of each face; unfolding changes neither the number nor the shapes. Example: a cuboid also has 6 faces, and if 2 are squares the other 6 - 2 = 4 are rectangles. Watch out: turn a dice in your hand while counting faces so none is missed.
Ringkasan
Syabas!
Kamu telah belajar tentang Kenali Bentangan Bentuk 3D.
Ingat: bentangan ialah bentuk yang dibuka; semak bilangan bentuk asas; bayangkan lipatan.
