Content

• Steps
• Warning

The total area of ​​a shape is the total area of ​​its faces. To calculate the total area of ​​the cylinder, we need to find the area of ​​the two bases and add the area around it. The formula for calculating the total area of ​​the cylinder is A = 2πr + 2πrh.

Steps

1. 

   Find the radius of a base. The two bases of the cylinder are the same size and area, so you can choose any bottom. In this example, the cylindrical radius is 3 cm. Please write it down. If the problem is for diameter only, divide it by 2. If the problem is perimeter, divide by 2π.

2. 

   
   
   Calculate the area of ​​the bottom. To find the area of ​​the base, replace the radius of the measurement (3 cm) into the formula for the area of ​​a circle: A = πr. We do the following:
   • A = πr
   • A = π x 3
   • A = π x 9 = 28.26 cm

3. 

   Duplicate the result to get a measure of the 2 bottoms. Simply multiply the result you found in the above step, 28.26 cm by 2 to get the area of ​​2 bases. 28.26 x 2 = 56.52 cm. So we have 2 bottom areas.

4. 

   
   
   Calculate the circumference of one of the two bases. You will need the circumference of the base to calculate the area around the cylinder. To get the base circumference, simply multiply the radius by 2π. Thus, to calculate the perimeter of the base in this case, multiply by 3 cm by 2π. 3 x 2π = 18.84 cm.

5. 

   Multiply the base's circumference by the height of the cylinder, and you'll get the area around. Take the base circumference, 18.84 cm, multiply by 5 cm height. 18.84 cm x 5 cm = 94.2 cm

6. 

   
   
   Add the surrounding area by the area of ​​the base. Add the area around the cylinder to the area of ​​the two bases, and we get the total area. All you need to do is get a base area of ​​56.52 cm plus the surrounding area of ​​94.2 cm. 56.52 cm + 94.2 cm = 150.72 cm. Thus, the total area of ​​a cylinder with a base radius of 3 cm and a height of 5 cm is 150.72 cm. advertisement

Warning

• If both the height and the radius have square roots, refer to How to multiply the square roots together and How to add and subtract the square roots for more instructions.