16.等腰三角形的两边的长分别为2cm和7cm,则三角形的周长是( )
| A. | 11 | B. | 16 | C. | 11或16 | D. | 无法计算 |
11.
如图,有两个长度相同的滑梯靠在一面墙上,已知左边滑梯的高度AC与右边滑梯水平方向的长度DF相等,且左边的滑梯与地面的夹角∠ABC=35°,则右边的滑梯与地面的夹角∠DFE=( )
| A. | 60° | B. | 55° | C. | 65° | D. | 35° |
8.下列运算正确的是( )
0 297337 297345 297351 297355 297361 297363 297367 297373 297375 297381 297387 297391 297393 297397 297403 297405 297411 297415 297417 297421 297423 297427 297429 297431 297432 297433 297435 297436 297437 297439 297441 297445 297447 297451 297453 297457 297463 297465 297471 297475 297477 297481 297487 297493 297495 297501 297505 297507 297513 297517 297523 297531 366461
| A. | (3x3)2=9x6 | B. | 2x3•x2=2x6 | C. | x3+x2=x5 | D. | x6÷x3=x2 |