Question

Нади площать поверхности прямоугольного паралепипеда длина 12 см ширина в 3 раза меньше длины а высота на 8 см бальше длины

Answer 1

12-3=9(ширина)
12+8=20(высота)
S=2(ab+bc+ac)
a=20;b=12;c=9
S=2(240+108+180)=2×528=1056(полного параллепипеда), а если надо найти боковой параллепипед то S=(240+108+180):2=528

Answer 2

Calculation of Surface Area of a Rectangular Parallelepiped

To find the surface area of a rectangular parallelepiped, we need to calculate the areas of its six faces and then sum them up.

Let's break down the given information step by step:

- Length of the parallelepiped: 12 cm - Width: 3 times smaller than the length - Height: 8 cm greater than the length

To calculate the surface area, we need to find the areas of the six faces:

1. Top face: The area of the top face is equal to the length multiplied by the width. 2. Bottom face: The area of the bottom face is also equal to the length multiplied by the width. 3. Front face: The area of the front face is equal to the length multiplied by the height. 4. Back face: The area of the back face is also equal to the length multiplied by the height. 5. Left face: The area of the left face is equal to the width multiplied by the height. 6. Right face: The area of the right face is also equal to the width multiplied by the height.

Let's calculate the surface area using the given dimensions:

1. Top and bottom faces: Since the width is 3 times smaller than the length, the width is 12 cm / 3 = 4 cm. Therefore, the area of the top and bottom faces is 12 cm * 4 cm = 48 cm². 2. Front and back faces: The height is 8 cm greater than the length, so the height is 12 cm + 8 cm = 20 cm. Therefore, the area of the front and back faces is 12 cm * 20 cm = 240 cm². 3. Left and right faces: The width is 4 cm, and the height is 20 cm. Therefore, the area of the left and right faces is 4 cm * 20 cm = 80 cm².

Now, let's sum up the areas of all six faces to find the total surface area:

48 cm² (top and bottom) + 240 cm² (front and back) + 80 cm² (left and right) = 368 cm².

Therefore, the surface area of the given rectangular parallelepiped is 368 cm².