24,149 views
42 votes
42 votes
I need help to find the surface area. I will send a clear photo.

I need help to find the surface area. I will send a clear photo.-example-1
User Iberbeu
by
2.7k points

1 Answer

22 votes
22 votes

To calculate the surface area of the object on the picture, you have to calculate the area of each face and then add them together.

The figure has 6 faces, each face is quadrilateral and the opposite faces are equal, which means that the shape has 3 pairs of congruent faces.

1. The top and bottom faces are rectangular, with length l=11cm and width w=16cm.

To determine the area of these faces you have to multiply the length by the width:


A=l\cdot w

Since both faces are equal, you have to multiply it by 2:


\begin{gathered} 2A=2(lw) \\ 2A=2(11\cdot16) \\ 2A=2\cdot176 \\ 2A=352\operatorname{cm}^2 \end{gathered}

2. The front and back faces are parallelograms with base b=11cm and height h=6.7cm.

To determine the area of a parallelogram you have to multiply its base by its height:


A=b\cdot h

As before, both faces are equal, to determine the area of both, multiply the area by 2:


\begin{gathered} 2A=2(bh) \\ 2A=2(11\cdot6.7) \\ 2A=2\cdot73.7 \\ 2A=147.4\operatorname{cm}^2 \end{gathered}

3. The remaining faces are rectangular with width w=16cm and height h=7cm.

To determine the area you have to multiply the width by the height:


A=w\cdot h

Once again, since there are two equal faces, you have to multiply the area by 2:


\begin{gathered} 2A=2(wh) \\ 2A=2(16\cdot7) \\ 2A=2\cdot112 \\ 2A=224\operatorname{cm}^2 \end{gathered}

Now that the area of all 6 faces of the shape is determined, you have to add them:


\begin{gathered} SA=352+147.4+224 \\ SA=723.4\operatorname{cm}^2 \end{gathered}

The surface area of the shape is 723.4cm²

User Abhiieor
by
3.1k points