(20 12? Hangzhou), as shown in the figure, is a part of the number axis, and the unit length is a. In the known △ABC, AB=3a, BC=4a, and AC = 5a. (1) Use a ruler and.
Solution: (1) As shown in the figure:
(2)2)∫△ABC's circumscribed circle area is S circle,
∴S circle =π×(AC2)2=25a24π,
△ABC S△ABC= 12×3a×4a=6a2 area,
∴S circle s delta = π 254a26a2 = 2524π > π.