A regular hexagon has side length of 15 centimeters and angles that measure 120 degree. Find FB to the nearest centimeters.

Answer 1

Note that in triangle ABF, we have AB = AF = 15 cm, and m∠BAF = 120°.

So

FB = sqrt(AB^2 + AF^2 - 2 × AB × AF × cos(120°))

= sqrt( 15^2 + 15^2 - 2 (15) (15) (- 1/2) ).

You should try to complete the calculation.