7ft = 84in 84 ÷ 15 = 5.6 pieces he can cut from each board. Since .6 is not a whole piece measuring 15 inches long, he can only cut 5 pieces from each board.
So, 5 x 2 = 10
He would be able to cut 10 pieces measuring 15 inches long.
Hope this helps :)
Answer:
Step-by-step explanation:
Y=cos(x+r/2)
Surface=2(5 x 4)+2(4 x 7)+2(5 x 7)=2(20)+2(28)+2(35)=40+56+70=166
Answer: 166 cm²