Question

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?

Answer 1

1. 
All three angles are equal and their sum is 180. 
3 (3x-12) = 180 
9x -36 = 180 
9x = 180+36 
9x = 216 
x = 216/ 9 = 24 

2. 
Area of an equilateral triangle = (sqrt(3)/4 ) s^2 = 270.633 
s^2 = 270.633 / [ sqrt(3) /4] 
s^2 = (4)(270.633) / sqrt(3) 
s^2 = 625 
s = 25 (side) 

Follow the procedure in the link: we don't need the altitude. 
r = 25/sqrt(3) =14.43 

Answer 2

Answer:

r = 14.4

Step-by-step explanation: