Preheat the oven to 400 degrees F (200 degrees C).

In a medium bowl, mix crushed pretzels, margarine, and sugar.

Press crushed pretzel mixture into the bottom of a 9x13-inch baking dish, and bake in the preheated oven, 8 minutes. Remove from heat and allow to cool.

Blend together cream cheese and sugar. Fold in whipped topping and spread evenly over cooled pretzel mixture.

In a medium bowl, dissolve strawberry-flavored gelatin in boiling water. Mix in strawberries and set aside to cool for 15 minutes.

Pour gelatin mixture over cream cheese mixture and refrigerate until set, about 4 hours.