Answer: A ≈ 271.7 square inches
Yes, you need to make the denominators the same. 2/3 becomes 8/12. So now you add 7/12 and 8/12, getting 15/12. But you're not done you need to simplify 15/12. The answer is 1 1/4.
90-69=21 degrees. This is our target answer. We'll write an equation to do this:
2x-1=21
Add 1 to each side to get:
2x=22
Divide by 2 to get that x=11
Plugging this in, we see that 2(11)-1+69=90, so our answer is correct.
:)
total surface area Stot = 1180 in2
lateral surface area Slat = 920 in2
top surface area Stop = 130 in2
bottom surface area Sbot = 130 in2