Question

find the area of circle circumscribing an equilateral triangle of side 15 CM( take π=3.14)

Answer 1

Solution:

Area of circle is 235.6 cm^2

Explanation:

Let us suppose ABC be the equilateral triangle inscribed in a circle of radius r and centered at point O.

Draw perpendicular OD that meets the base BC at D.

Hence, BD = 7.5 cm.

Since, the radius of the triangle bisects the angle B. Hence,  we have

$\angle OBD = 30^{\circ}$

In right angle triangle OBD, we have

$\cos 30^{\circ} = \frac{7.5}{r} \\\\r=\frac{7.5}{\cos 30^{\circ} } \\\\r=5\sqrt3$

Therefore, the area of the circle is given by

$A=\pi r^2\\\\A=3.14(5\sqrt3)^2\\\\A=235.6 cm^2$

Answer 2

Answer:

235.6 cm2

Step-by-step explanation:

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