The lengths are in cm!

Me write an equation for the interior angles of this triangle that uses the triangle sum theorem

Ricardo ran the 400 meter race 3 times his fastest time was 54.3 seconds his slowest time was 56.1 seconds if his average time was 55.0 seconds what was his time for the third race

Mindy bought 5/8 pound of almonds and a 3/4 pound of walnuts. which pair of fraction cannot be used to find how many pounds of nuts she bought in all.