Traditional Culture Encyclopedia - Photography major - Senior two mathematics

Senior two mathematics

Let the radius of the ball be r,

Because the surface area of the ball is 400π, the radius of the ball is r = 10.

Because SA=SB=SC, the photography d of the vertex s of the triangular pyramid in the bottom ABC is the epicenter of △ABC.

Because < ACB = 90 degrees,

So d is the midpoint of AB,

So the distance from point O to ABC is h = od.

Because SA=SB=AB, it can be concluded that △SAB is an equilateral triangle.

So point O is the outer center of the triangle △SAB, which is the center of the triangle.

Because its circumscribed circle radius is 10, OD = 5.