Patent ID: 7137207

Claim:
A method of defining a 90 degree angle for positioning the corner of a building foundation, using a measurement and positioning device for defining a 90 degree angle for positioning the corner of a building foundation, said measurement and positioning device comprising: a hook structure being configured to hang said device from a string tied between two stakes; and at least one laser beam projector being configured to project a laser beam from said measurement and positioning device substantially perpendicular to a string from which said measurement and positioning device is suspended to define a 90 degree angle and a location where a corner of a building foundation will be placed; said method comprising the steps of: placing a first stake and a second stake in the ground on a line where a side of a building foundation will be located; tying a string between said first stake and said second stake; hanging said measurement and positioning device from said string; and switching on said measurement and positioning device to supply power to said at least one laser beam projector to project a laser beam from said measurement and positioning device substantially perpendicular to said string to define a 90 degree angle and a location where a corner of a building foundation will be placed.