创新角度1:三视图、几何体、外接球三位一体求球的表面积例1四棱锥P-ABCD的五个顶点都在一个球面上,该四棱锥的三视图如图1所示.E,F分别是棱AB,CD的中点,直线EF被球面所截得的线段的长为22~(1/2),求该球的表面积.解四棱锥P-ABCD的直观图如图2所示.∵四棱锥P-ABCD可看成正方体的一部分,∴PC为正方体外接球的直径.由直线EF被球面所截得的线段的长为22~(1/2),可知正方形ABCD Innovation perspective 1: three views, geometry, external ball trinity surface area of ​​the ball Example 1 quadrangular pyramid P-ABCD five vertices are in a sphere, the three pyramid view of the three shown in Figure 1. E, F were Oblique AB, CD of the midpoint of the straight line EF by the spherical surface of the line length of 22 ~ (1/2), find the surface area of ​​the ball. Pyramid Pyramid P-ABCD visual map shown in Figure 2. ∵ Pyramid P-ABCD can be seen as part of the cube, ∴ PC is the diameter of the cube outside the ball by the straight line EF is spherical cross-sectional length of 22 ~ (1/2), we can see the square ABCD