Outside corner square

Claim 1

A square adapted for use on outside corners formed by approximately right angularly arranged first and second surfaces and an outwardly projecting obstruction at the corner, said square comprising first and second right angularly arranged arms each having a precise inwardly facing linear edge surface for engagement with said first and second surfaces, each of said arms terminating a substantial distance from an imaginary inside corner residing at the intersection of first and second lines projected respectively from said inwardly facing linear edge surfaces on said arms, and means interconnecting said first and second arms at their ends proximate said imaginary inside corner and maintaining said arms in said right angular relationship, said interconnecting means taking a generally particircular form with opposite ends thereof connected respectively with said proximate ends of said arms and with an intermediate portion thereof extending arcuately outwardly from said opposite ends and defining a clearance opening in the general shape of a segment for receiving said outwardly projecting obstruction at the corner of said first and second corner surfaces and thus enabling said linear arm inner edge surfaces to engage said corner surfaces, and said arms being provided with indicia of measurement serially spaced therealong from their said ends proximate said imaginary corner and referenced to said imaginary corner.