Re: What is the surface area of a right rectangular cylinder with a radius
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09 Dec 2022, 03:00
OE
C It’s a geometry problem with variables in the answer choices, so draw the figure and set up your scratch paper to Plug In. Plug in an easy number like r = 5; label the radius 5 and the height 15, which is 1.5 times your diameter of 10. The surface area of a cylinder is made up of 3 smaller areas: 2 identical circular bases on top and bottom, and a rectangle that’s the height of the cylinder on one side and the circumference of the base on the other. If r = 5, then the area of each base is 25π, or 50π for the 2 of them. The rectangle is 15 × 10π = 150π, so the total surface area is 200π, your target answer. Plug 5 in for r in the answers, and only choice (C) matches your target answer of 200π.