Question

Solve triangle ABC given:

(a) angle A = 40°, angle B = 60°, b = 8 cm.
(b) a = 4, b = 5, c = 6.
(c) angle B = 104°, a = 17 cm, c = 11 cm.

Answer 1

(a) C = 80 a = 5.938cm c = 9.097cm

(b) unsure

(c) b= 22.147cm

A = 48.16 degrees

C = 22.82 degrees

Note angle sum higher than 180 due to rounding inaccuracies

Explanation:

(a) <C == 180 - (40 + 60) == 80 (Interior angles on triangle have sum of 180 degrees)

side a = (8*sin(40))/sin(60) == 5.938cm by law of sines

side c = (8*sin(80))/sin(

60) == 9.097cm by law of sines

(b) unsure

(c) b^2 = 17^2 + 11^2 - 2(17)(11)cos(104) --> Law of cosines

b^2 = 289 + 121 - 2(187)cos(104)

b^2 = 400 - -90.479

b^2 = 490.479

b = 22.147 cm

sin(A)/17cm = sin(104)/22.147cm

A = arcsin((17/22.147)*sin(104))

A = 48.16 degrees

sin(C)/11cm = sin(104)/22.147cm

C = arcsin((11/22.147)*sin(104))

C = 28.82 degrees