## chancemorris123 one year ago Find the surface area of the composite solid. Round your answer to the nearest hundredth.

1. chancemorris123

2. UnkleRhaukus

The total surface area of the composite solid, can be decomposed into three areas: 1 the circular base 2 the lateral surface area of the cylinder (a rectangle) & 3 the lateral area of the cone (a sector)

3. UnkleRhaukus

The area of a circle (or radius $$r$$) is : $A_\text{circle} = \pi r^2$

4. UnkleRhaukus

The area of a rectangle (of width $$w$$, height $$h$$) is: $A_\text{rectangle} = w\times h$

5. chancemorris123

so i tryed it and got c is that right

6. UnkleRhaukus

i don't know,

7. chancemorris123

that makes to of us

8. UnkleRhaukus

The area of the sector (of radius $$r$$, and slope $$s$$) is: $A_\text{sector} = \pi r s$

9. UnkleRhaukus

add them all together, what do you get ? (before plugging in the numbers)

10. chancemorris123

i put c and i only got 30 min :( and got 6 more questions

11. UnkleRhaukus

i dont know what the answer is, we have to work it out

12. UnkleRhaukus

$SA_\text{total} = A_\text{circle}+A_\text{rectangle}+A_\text{sector}\\ \qquad\quad= \quad. . .$

13. chancemorris123
14. chancemorris123

never mind that one i guessed cuz ii need to do the rest befopre time runs out

15. UnkleRhaukus

NB: the width of the rectangle the circumference of a circle $w =C = 2\pi r$

16. UnkleRhaukus

$SA_\text{total} = A_\text{circle}+A_\text{rectangle}+A_\text{sector}\\ \qquad\quad= \pi r^2+2\pi r h+\pi rs\\ \qquad\quad= \pi r(r+2h+s)\\ \qquad\quad= \quad. . .$