2. The waist height of an isosceles triangle is 1, and the angle between the height and the bottom is 60, so the area of this triangle is (c)A, 2√3 B, 1/3 √3 C, 1/3 √3 D, 2.
3. If the median line of one side of a triangle is equal to half of this side, then this triangle is (C).
A, acute triangle B, obtuse triangle C, right triangle D, uncertainty
4. In the oblique triangle ABC, BE and CF are higher, so the size relationship between ∠ABE and ∠ACF is (C).
A, ∠ Abe < ∠ ACF B, ∠ Abe > ∠ ACF C, ∠ABE=∠ACF D, uncertain.
5. If the height on the bottom of an isosceles triangle is 8 and the circumference is 32, the area of the triangle is (b).
a、56 B、48 C、40 D、32