Answer:
First find line DE using Pythagoras theorem
That's
DE² = 7² + 24²
DE = √ 49 + 576
DE = 25
The correct trigonometric ratio for triangle DEF is
Cos(E) = 24/25
Hope this helps
To find the surface area of a cylinder, use the formula SA = 2(pi)(radius^2) + 2(pi)(radius)(height).
So now, plug in what you know.
SA = 2(3.14)(5^2) + 2(3.14)(5)(9)
SA = (6.28)(25) + (6.28)(45)
SA = 157 + 282.6
SA = 439.6 square cm
439.6 square cm is your surface area
400 - 3x = 163
Add 3x to both sides.
400 = 163 + 3x
Subtract 163 to both sides.
237 = 3x
237/3 = 79
