Final answer:
Thrust blocks do not have to be square. The shape depends on soil type and other factors.
Step-by-step explanation:
The correct answer is B) False. All thrust blocks do not need to be square in shape in order to develop maximum bearing area. The shape of a thrust block depends on the specific requirements of the application.
For example, if the soil being dealt with has cohesive properties, a circular thrust block may be more effective as it can distribute the thrust forces evenly. On the other hand, for non-cohesive soils, a square or rectangular shape may be more suitable.
It is important to consider the soil type and other factors when determining the shape of a thrust block for maximum bearing area.