Seemingly, Gold Triangle would have just been the discount division of Burdine's or Jordan Marsh. However, this was not quite the case. It was a hard lines store best described as carrying "recreational, home and electronics" products . The closest relative to it is the also defunct Lechmere stores, which were operated by Montgomery Ward. Gold Circle got its start in 1968. Three stores opened in Fort Lauderdale, Dadeland and Skylake Mall in 1970. As a side note, it should be noted that Skyland Mall, built in 1959, was demolished in 2000. At its peak, the chain grew to six stores, all in the Miami and West Palm Beach area. The chain also had one store in the Tampa area, though I have no information on that. Though operated by Federated, the chain was Hialeah, FL-based.
In November 1981, it was announced that Gold Triangle would liquidate and close down the entire chain. Apparently the odd format proved ultimately to be unprofitable, but this did not mean that Gold Triangle was being sold off. Instead, Federated decided to bring its Atlanta-based Richway division to Florida. Opening in 1982, the new Richway stores absorbed all six former Gold Triangle locations, also bringing an unfamiliar discounter to the Sunshine State. This will also explain earlier comments about a lack of the wedge skylights on the Richway stores in Florida, which would have been oddly very appropriate for a store with "triangle" in the name. However, as images below will show, the building itself had a triangular shape. They obviously were successful, though, and these continued to operate as such until the sale to Target in 1989.
To add to confusion, it is also possible that these stores may have briefly operated as Gold Circle. Gold Circle and Richway were merged in 1986 prior to the liquidation in 1988. Federated also absorbed another chain into the Richway family when they purchased two former Gibson's locations in Chattanooga, TN somewhere in the same period. The former Gold Triangle/Richway stores have mostly been abandoned in the South Florida market today, but they left a recognizable and familiar legacy similar to its home base, which is quite unique.
Former Gold Triangle/Richway store on 1941 S Military Trail. Image from Google Street View.
Today, Target continues to operate in three of the six original Gold Triangle locations. All three of those Target locations were rebuilt. The one across from defunct Palm Beach Mall was the last to retain the Gold Triangle look. Previously, five of the Gold Triangle stores converted to Richway. One, at fore-mentioned Skyland Mall failed to be converted to Richway. The other two have since closed and been relegated to other uses, including the one pictured above that is now "Sunshine Market". Gold Triangle stores had a very interesting design indeed.
1760 Palm Beach Lakes Blvd location prior to demolition and reconstruction as a two story store in 2009. Image from Google Street View.
Here is the list of the South Florida Richway locations which previously operated as Gold Triangle:
8201 W Federated Roadway (Plantation)
1200 S Federal Highway (Deerfield Beach)
8399 N University Dr (Tamarac)
1941 Military Trail (Palm Springs)
1760 Palm Beach Lakes Blvd (West Palm Beach)
 Hughes, Le A. "Gold Triangle stores to close after Christmas". The Miami News. 17 November 1981.