1) A a^2+b^2 =c^2 where c is the hypotenuse 6^2+5^2=c^2 36+25=c^2 c^2=61 take square root of both side c= √61
2) C same concept, but now we already have c, just need to find the other leg measurements (let’s call it a but it doesn’t matter a or b is fine) a^2+19.5^2=20^2 a^2=20.2^2-19.5^2 take square root a= √20.2^2-19.5^2
