Hi, I have a question on circle geometry... Its looks quite simple (I would think) but I dont know how to do it. Two circles of radii 5cm and 8cm touch each other externally. Calculate the length of the common tangent. Thanks.
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If you draw the diagram correctly, then you will see a trapezoid with two right angles as base angles. The lengths of the two parallel sides are 5 & 8. The length of the summit is 13. Thus you need to find the length of the base.
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