1. At closed cylinder has radios 3 cm and height 7 cm . Find its tatal surface area

To find the total surface area of a closed cylinder, we need to calculate the area of the two circular bases and the area of the curved surface. Given: - Radius of the cylinder = 3 cm - Height of the cylinder = 7 cm The formula for the total surface area of a closed cylinder is: \[ \text{Total Surface Area} = 2 \pi r^2 + 2 \pi r h \] Where: - \( r \) is the radius of the cylinder - \( h \) is the height of the cylinder Substitute the given values into the formula: \[ \text{Total Surface Area} = 2 \pi (3)^2 + 2 \pi (3) (7) \] Now, we can calculate the total surface area. Calculate the value by following steps: - step0: Calculate: \(2\pi \times 3^{2}+2\pi \times 3\times 7\) - step1: Multiply the terms: \(18\pi +2\pi \times 3\times 7\) - step2: Multiply the terms: \(18\pi +42\pi \) - step3: Collect like terms: \(\left(18+42\right)\pi \) - step4: Add the numbers: \(60\pi \) The total surface area of the closed cylinder is approximately 188.5 cm².