.45 caliber? B.60？ C.90？ D. 180
2.(20 12? Zhaoqing) The lengths of the two sides of the isosceles triangle are 4 and 8 respectively, so the circumference of the isosceles triangle is ().
A. 16？ B. 18？ C.20？ D. 16 or 20
3.(20 12? Yiwu) If two sides of a triangle are 3 and 5, and the third side is even, then the third side can be ().
A.2？ B.3？ C.4？ D.8
(20 12? As shown in the figure, in △ABC, the bisector of ∠ABC and ∠ACB intersects with point E, and the intersection point E is MN∨BC intersects with AB in M and AC in N. If BM+CN=9, the length of the line segment MN is ().
A.6？ B.7？ C.8？ D.9
4.(20 10? Taizhou) As shown in the figure, at △ABC, ∠ C = 90, AC=3, and point P is the moving point on the side of BC, then the length of AP cannot be ().
A.2.5？ B.3？ C.4？ D.5
5.(2006? Liuzhou) Cut off a corner of a polygonal piece of paper, leaving a quadrangle, so the original shape of this paper can't be ().
A. hexagon? Pentagon? C. quadrilateral? D. triangle
You can travel to Beijing. For details, please visit. As you are in the sixth grade, you only found five slightly simpler ones. . .