14

Part of 1989 National High School Mathematics League

Problems(1)

3D Geometry Problem

Source: 1989 National High School Mathematics League, Exam One, Problem 14

In regular triangular pyramid

S-ABC

SO=3

, length of sides of bottom surface is

6

. Projection of

A

SBC

O'

P\in AO',\frac{AP}{PO'}=8

. Draw a plane parallel to plane

ABC

P

. Find the area of the cross section.

geometry3D geometrypyramid