What radius of a circle is required to inscribe an equilateral triangle with an area of 270.633 cm2 and an altitude of 21.65 cm? (round to nearest tenth)

Respuesta :

The answer will be 14.4cm

Answer:

The radius of the circle is 14.4 cm.

Step-by-step explanation:

Let a be the side of the equilateral triangle and r be the radius.

The area of a triangle is given by

[tex]A=\frac{1}{2}\cdot a\cdot h\\\\270.633=\frac{1}{2}\cdot a\cdot 21.65\\\\a=25.0007[/tex]

We have calculate the side of the triangle. From the figure,

[tex]BD=\frac{a}{2}\\\\BD=\frac{25.0007}{2}\\\\BD=12.50035[/tex]

Hence, in triangle OBD, we have

[tex]\cos30^{\circ}=\frac{BD}{r}\\\\\frac{\sqrt3}{2}=\frac{12.50035}{r}\\\\r=14.4[/tex]

The radius of the circle is 14.4 cm.

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