Lateral Force and Pressure on a dam

[designer rose]

1a. What is the total lateral force on a vertical dam 75 ft high and 135 ft wide if the water comes up to the very top of the dam?

I think I got the answer to this one, is it 2.4 x 10^7?

1b. What is the pressure on the lake bottom next to the dam?

 

[Q_Goest]

Show how you got 1a please.

If you got 1a, then how did you resolve the pressure distribution across the face of the dam?