Star Paving (D) submitted a bid by phone on a public school building in response to a request for bids from Drennan (P), the general contractor on the job. P took D's bid of $7,131.60 and recorded it on his master sheet. It was custom in the area for general contractors to accept bids by phone and to rely on them in determining their own bids. D's bid was the lowest one, and P used it in preparing his final bid. P was required to secure its bid with a performance bond. P was awarded the contract that evening. The next day D told P that its bid was in error and the real cost should have been $15,000. D refused to do the work for less than $15,000. P found another contractor to do the work for $10,948.66. P sued D for the difference in costs. The trial court found that D had made a definite offer and that P had relied upon that offer when he listed D as the subcontractor. Judgment was entered for P. D appealed.