挑战习题
1/3单选题
难度:

1.在△ABC中,角A,B,C分别对应边为a,b,c,b=acosC,则△ABC的形状为(    )
A 等腰三角形
B 直角三角形
C 等边三角形
D 等腰三角形或直角三角形
提示1:
IOeUsWI9YWNvc0PlkozmraPlvKblrprnkIblvpdzaW5CPXNpbkFjb3ND
正确答案:Qg==
6Kej77yaYj1hY29zQ+eUseato+W8puWumueQhuW+l++8mnNpbkI9c2luQWNvc0M8YnI+4oi1Qj3PgC3vvIhBK0PvvInvvIw8YnI+4oi0c2luQj1zaW7vvIhBK0PvvIk9c2luQWNvc0M9c2luQWNvc0MrY29zQXNpbkM8YnI+4oi0Y29zQXNpbkM9MDxicj7lj4hB77yMQ+KIiO+8iDDvvIzPgO+8ie+8jDxicj7iiLRjb3NBPTDvvIxBPTxpbWcgd2lkdGg9MTggaGVpZ2h0PTQyIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvRkQvOTkvckJBQ0UxTlFuaF9qcjk4MEFBQUJqVm9zWmtBNzc5LnBuZyI+PGJyPuKItOKWs0FCQ+aYr+ebtOinkuS4ieinkuW9og==