How to find surface area and volume of a cone

Surface area:We know that the base of a cone is a circle, which has a surface area of πr², where r is the radiusThe rest of the area will be π, r and l (the slanted length) multiplied togetherAnd then, we just add them together: πr²+πrl
Volume:We can think of a cone's volume as a third of a cylinder's volume of the same height and radius (can explain more with a diagram)The cylinder's volume is the base times the height= πr²hTherefore, the cone's volume is equal to (πr²h)/3(note: sorry if these look messy, I couldn't save rows as separate)