hi im doing surface area I wondering how do you get the answer . this is the question
Find the total surface area of a rectangular prism having dimension
1) 45cm by 30cm by 20cm
http://www.aaamath.com/geo79_x9.htm
2(45 * 30) + 2(45 * 20) + 2(30 * 20) = ?
To find the total surface area of a rectangular prism, you need to calculate the areas of all its faces and then add them together.
A rectangular prism has 6 faces: a top and bottom face, two side faces, and two front and back faces.
To find the areas of each face, you can use the formula: area = length x width.
For the given dimensions of the rectangular prism being 45cm by 30cm by 20cm, you can calculate the areas as follows:
1) Top and bottom faces:
The dimensions are 45cm by 30cm, so the area of each face is:
Area = 45cm x 30cm = 1350cm²
2) Side faces:
You have two side faces, each with dimensions 45cm by 20cm.
The area of each side face is:
Area = 45cm x 20cm = 900cm²
Since there are two side faces, the total area for both of them is:
Total Area = 2 x 900cm² = 1800cm²
3) Front and back faces:
You also have two front and back faces, each with dimensions 30cm by 20cm.
The area of each front/back face is:
Area = 30cm x 20cm = 600cm²
Since there are two front/back faces, the total area for both of them is:
Total Area = 2 x 600cm² = 1200cm²
Now, to find the total surface area, you add up all the individual areas:
Total Surface Area = Top + Bottom + 2 x Side + 2 x Front/Back
Total Surface Area = 1350cm² + 1350cm² + 1800cm² + 1200cm²
Total Surface Area = 4500cm²
Therefore, the total surface area of the rectangular prism is 4500cm².