Question

FIND THE SURFACE AREA OF THE FOLLOWING SHAPES! Round to the nearest tenth IF NECESSARY!

Answer 1

Answer:

1. $360cm^{2}$

2. $A=1657.9mi^{2}$

3. $A=215.8ft^{2}$

4. $204ft^{2}$

Step-by-step explanation:

1. Find the area of the base. 10×10=100. Now, find the area of one of the triangles. 5×13=65. Multiply 65 by 4. Now, add this number to 100. 100+260=$360cm^{2}$

2. Divide the diameter by 2 to get the radius. r=12. h=10. $A=2\pi rh+2\pi r^{2}$. $A=2(3.14)(12)(10)+2(3.14)(12)^{2}$. $A=6.28(12)(10)+2(3.14)(12)^{2}$. $A=75.36(10)+2(3.14)(12)^{2}$. $A=753.6+2(3.14)(12)^{2}$. $A=753.6+6.28(12)^{2}$. $A=753.6+(6.28)(144)$. $A=753.6+904.32$. $A=1657.9mi^{2}$

3. $A=\pi r(r+\sqrt{h^{2}+r^{2} })$. r=4. h=12.6. $A=(3.14)(4)(4+\sqrt{12.6^{2} +4^{2} } )$. $A=12.56(4+\sqrt{12.56^{2}+4^{2} } )$. $A=12.56(4+\sqrt{157.756 +4^{2} } )$. $A=12.56(4+\sqrt{157.7536+16} )$. $A=12.56(4+\sqrt{173.7536} )$. $A=12.56(4+13.1815)$. $A=12.56(17.1815)$. $A=215.8ft^{2}$

4. Find the area of the base. 9×4=36. Multiply this by two to get the base and the top. This is 72. Now, find the front side area. 9×3=27. Multiply this by two to get the front and back sides. This is 54. Now, find the area of the left side face. 4×3=12. Multiply this by 2 to get both sides. This is 24. Add 72+54+24=$204 ft^{2}$