| 摘要 |
Through its unique trapezoidal shape and 11 vials, the combination level and right angle measuring tool requires only one user to not only quickly and precisely verify if a long object is level or plumb but also to easily and accurately determine if the angle of the intersection of two long objects is 90 degrees by employing the 3-4-5 measuring rule (an application of the Pythagorean Theorem, where a2+b2=c2) in its design. |
