Answer:
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
Answer:
A =75.86, B=36, C=68.14, b=19, c=30, a=31.34
A=32.14, B=36, C=111.86, b=19, c=30, a=17.19
Step-by-step explanation:
We have two sides of triangle (b and c) and an angle (B)
To solve the triangle we use the sine theorem:
[tex]\frac{sin(B)}{b}=\frac{sin(C)}{c} =\frac{sin(A)}{a}[/tex]
We substitute the values of b, B and c in the equation and solve for C
[tex]\frac{sin(36)}{19}=\frac{sin(C)}{30}\\\\sin(C) = 30*\frac{sin(36)}{19}\\\\sin(C) = 0.9281\\\\C=arcsin(0.9281)\\\\C=68.14\°\ \ or\ \ C=111.86[/tex]
The sum of the internal angles of a triangle is 180, then
[tex]68.14 + 36 + A=180\\\\A=180-68.14 - 36\\\\A=75.86\°[/tex]
or
[tex]111.86 + 36 + A=180\\\\A=180-111.86 - 36\\\\A=32.14\°[/tex]
No we find "a" for both cases.
[tex]\frac{sin(36)}{19}=\frac{sin(75.86\°)}{a}\\\\0.03094a=sin(75.86\°)\\\\a=\frac{sin(75.86\°)}{0.03094}\\\\a=31.34[/tex]
or
[tex]\frac{sin(36)}{19}=\frac{sin(32.14\°)}{a}\\\\0.03094a=sin(32.14\°)\\\\a=\frac{sin(32.14\°)}{0.03094}\\\\a=17.19[/tex]
