Mathematics
Three circles of radii 2 cm, 3 cm and 4 cm touch each other externally. Find the perimeter of the triangle obtained on joining the centres of these circles.
Circles
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Answer
Three circles with centres A, B and C touch each other externally and the radii of these circles are 2 cm, 3 cm and 4 cm respectively.
From figure,
By joining the centres of circles, triangle ABC is formed in which,
AB = 2 + 3 = 5 cm
BC = 3 + 4 = 7 cm
CA = 4 + 2 = 6 cm.
Therefore, perimeter of the triangle ABC = AB + BC + CA = 5 + 7 + 6 = 18 cm.
Hence, the perimeter of triangle ABC = 18 cm.
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