Red triangle and warning yellow symbols

My 2005 Prius has about 141000 miles on it. The red triangle exclamation point comes on the dash and a yellow exclamation comes on the LCD 1st and then a 2nd yellow symbol comes on the LCD. The problem happens once or twice a day. It seems to start, run, and drive just fine. I was wondering if anyone could tell me the problem and/or how much it will cost to fix. I do restore antique tractors and I am pretty good with computers and I have some pretty good mechanical know how. Attached are pictures of the lights. Please help.