Please draw a cube ABCD-A1b 1C1D1,and connect AB 1, B1C, AC, AD 1, CD/Kloc-. Then I analyze why the top view is square. Because the so-called three views are actually light projected on an object and then projected on the wall. For example, if light shines from top to bottom, the projection of side length AD 1 is AD, and the projection of side length D 1C is DC. The projection of B 1C is BC, and the projection of AB 1 is AB, that is to say, the top view is a square ABCD of a cube. So we get a cube with a side length of 2 cm. Then say the front view of the regular tetrahedron. Because the shape of the three views is related to the direction of the object, such as a cuboid, the three views have different ways. As can be seen from the top view, the drawn cube should face you with the edge of AA 1, instead of ABB 1A 1. Therefore, the front view is triangular, not square like the top view. The front view is an isosceles triangle with B 1D 1 as the base equal to 2√2cm and C 1C as the height greater than 2. So the area is 2√2.

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