If you’re supposed to be using Pythagorean theorem, a^2+b^2=c^2, then you square the 10 and the 7, getting 100 and 49. Subtracting the 49 from the 100 gives you b^2. 100-49=51. Then you take the square root of 51, which is about 7.1 Are you supposed to be rounding to the nearest whole number? If you did, that would make the missing side 7, and both of your missing angles 45.