What is BC?

Thank you for anyone who answers

Use the formula a squared + b squared= c squared so 12x12= 144+ b squared = 1369
Subtract 1369-144=1225 then root that and get 35 35

1. 0.3 •4 is the same as 4 groups of 0.32. 7•0.8 is the same as 7 groups of 0.83. it increases by 0.5 every time, so 0.5x4 it increases by 0.9 every time, so 0.9x5. 0.9•12=10.86. 0.47•5=2.35i can finish the next ones in a separate post