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ROSECODE 452

Equilateral triangles 4

liuguangxi · Probability ·

Assume a point D inside an equilateral triangle ABC of side length 3. Then we can use the three segments AD, BD and CD to build a new triangle PQR.

When point D is in the center of triangle ABC, the area of triangle PQR is 3/4, which is the maximum value for all possible positions of D; and the circumference of PQR is 3, which is the minimum value. Moreover, when point D is close to the vertex of triangle ABC, the area of triangle PQR is close to zero; and the circumference of PQR is close to its maximum value 23.

Assuming that point D is chosen randomly (with uniform distribution) within triangle ABC, find the expected area and circumference of triangle PQR. Give your answers rounded to 8 digits after the decimal point.

Answer format: [expectation of area],[expectation of circumference]
(Sample input: 0.43301270,3.46410162)