A triangle has two corners with angles of pi / 4 π4 and pi / 6 π6. If one side of the triangle has a length of 16 16, what is the largest possible area of the triangle?

1 Answer
Feb 13, 2018

largest possible area of the triangle color(purple)(A_t ~~ 699.405At699.405

Explanation:

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Third angle C = pi - pi/4 - pi/6 = (7pi)/12C=ππ4π6=7π12

To get the largest possible area, length 16 should correspond to least angle pi/6π6

Other sides are

a / sin(pi/4) = b / sin (7pi)/12 = c / sin (pi/6) = 16 / sin (pi/6) = 32asin(π4)=bsin(7π)/12=csin(π6)=16sin(π6)=32 as sin(pi/6) = sin 30 = 1/2sin(π6)=sin30=12

a = 32 sin (pi/4) = 32 sqrt2 = 45.2548a=32sin(π4)=322=45.2548

Area of triangle A_t = (1/2) a c sin B = cancel(1/2) cancel(32)^color(red)(16) sqrt2 * 32 * sin ((7pi)/12)

A_t = 512 sqrt2 sin ((7pi)/12) = color(purple)(699.405 sq units