A triangle has sides A,B, and C. If the angle between sides A and B is (3pi)/8, the angle between sides B and C is pi/6, and the length of B is 10, what is the area of the triangle?

1 Answer
Jun 5, 2018

"Area " ~~ color(red)(23.3 " sq units"

Explanation:

3/8pi+pi/6=13/24pi so the third angle is 11/24pi

using the sine rule

10/[sin(11/24pi)]=c/[sin(3/8pi)]

c ~~color(red)( 9.32

area=1/2absinC

area=1/2 xx 10 xx color(red)(9.32) xx sin (pi/6)

#"Area = (1/2) * 10 * color(red)(9.32) * (1/2)

"Area " = (10/4) * 9.32 = 2.5 * 9.32 ~~ color(red)(23.3 " sq units"