Cream margarine with 3 tbsp. Sugar, add pretzels. Press mixture into 9 x 13 x 2” baking dish or pan. Bake at 350 degrees for 10 minutes. Cool Mix cream cheese, Cool Whip, and remaining sugar until well blended. Pour over pretzel mixture. Make the gelatin with 2 cups boiling water, stir in frozen strawberries and put the mixture in refrigerator and chill until slightly thickened (about 4 minutes). Remove mixture from refrigerator and pour over salad. Keep refrigerated.