Find all solutions for a triangle with B = 36º. b = 19, and c = 30. Round to the nearest tenth.

m∠A = 76° , m∠C = 68° , a = 31.4

Step-by-step explanation:

* Lets revise how to solve a triangle

- In ΔABC

- a, b, c are the lengths of its 3 sides, where

# a is opposite to angle A

# b is opposite to angle B

# c is opposite to angle C

- m∠B = 36°  

- b = 19  

- c = 30

* To solve the triangle we can use the sin Rule

- In any triangle the ratio between the length of each side  

to the measure of each opposite angle are equal

- a/sinA = b/sinB  = c/sinC

* Lets use it to find a and m∠C

∵ m∠B = 36° , b = 19 and c = 30

∵ 19/sin36° = 30/sinC ⇒ by using cross multiplication

∴ sinC = 30 × sin36° ÷ 19 = 0.928

∴ m∠C = sin^-1(0.928) = 68°

- Find measure of angle A

∵ The sum of the measures of the interior angles in a triangle is 180°

∵ m∠A = 180° - (68° + 36°) = 180° - 104° = 76°

∴ m∠A = 76°

- Now we can Find a

∵ a/sinA = b/sinB

∴ a/sin76° = 19/sin36° ⇒ by using cross multiplication

∴ a = 19 × sin(76°) ÷ sin(36°) = 31.4

* m∠A = 76° , m∠C = 68° , a = 31.4