In
an isosceles triangle ABC, the measure of angle B is 20 degrees, AB = BC =
a, and AC = b. Prove that (1) a3 + b3 = 3a2b,
(2) ; (3)
; (4)
; (5)
.
This entry contributed by Sumith Peiris, Moratuwa, Sri Lanka.
See also:
Geometry
problem 1271
in motion.