Find the Surface Area of the figure.
Question options:
24 square units
48 square units
88 square units
44 square units
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Which angle has the same measure of the dihedral angle formed by the green face and the purple rectangle?
Question options:
Angle JAB
Angle HAJ
Angle JAE
Angle JDC
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#1)
One way to approach this problem is to add up the sides of all the faces. All the faces are rectangular-shaped, so finding their individual area is not too difficult.
\(A_{\text{AGFD}}=lw\) | This is the formula for the area of this side. Its length (l) is 6 units, and the width (w) is 4 units. |
\(A_{\text{AGFD}}=6*4\) | |
\(A_{\text{AGFD}}=24\text{ square units}\) | Area is always represented as a square unit since it measures in two dimensions. |
We can do the same calculation for the other faces.
\(A_{\text{ABCD}}=lw\) | Use the diagram to find these lengths. |
\(A_{\text{ABCD}}=6*2\) | |
\(A_{\text{ABCD}}=12\text{ square units}\) | |
\(A_{CDFE}=lw\) | We might as well find the other one, too. |
\(A_{\text{CDFE}}=4*2\) | |
\(A_{\text{CDFE}}=8\text{ square units}\) | |
Because the above figure is a rectangular prism, the opposite face is equal to one that I already found.
\(SA_{total}=2(A_{\text{AGFD}}+A_{\text{ABCD}}+A_{\text{CDFE}}\) | Let's plug in the values we know. |
\(SA_{total}=2(24+12+8)\) | One luxury unique to addition and multiplication is that you can perform the calculation in any order you desire; therefore, I will find the sum of 12 and 8 because they add up to a number where its last digit is zero. |
\(SA_{total}=2(24+20)\) | |
\(SA_{total}=2(44)\) | |
\(SA_{total}=88\text{ square units}\) | |
#2)
A dihedral angle is formed when two planes intersect. \(\angle JAB\) has the same measure because it is included in the dihedral angle.