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The length of a rectangle is greater than its breadth by 3m. If its area is 210 m using the completing square method, what is the value of the perimeter of the rectangle?

breadth/width = m. length = m+3

m(m+3) = 210

m²+3m =210

m²+3m+1.5² = 210+1.5²

(m+1.5)² = 212.25

m+1.5 = √212.25

m = √212.25–1.5

length = √212.25–1.5+3 = √212.25+1.5

perimeter = 2([√212.25–1.5]+[√212.25+1.5])

perimeter = 2√212.25