Make the 3 content area windows on Melos theme, main pagee the same size

Hello, i am using the Melos theme and the 3 content area windows on my page, where i have a picture of a debt ball and chain, another picture of a 1+1=2 sign and another one of a clock. i am looking to make those three content areas the same size. as you can see from my page if you look at the bottom of those content areas, they are not the same dimensions. Can you help me with this? my page is below. i know when i add new text, the frames seem to resize, but im wondering how would i change them to the same size.

https://ec2-52-32-78-210.us-west-2.compute.amazonaws.com/

Thanks!