60 /1 = 120 /2 = 180 /3
hope it helps
Answer:
1. 180
2. x = 31
Step-by-step explanation:
1. the sum of the interior angles of every triangle is always 180
2. using what we know from problem 1, we can create an equation:
x + 10 + 2x - 5 + 2x + 20 = 180
add like terms: 5x + 25 = 180
subtract 25 from both sides: 5x = 155
divide both sides by 5: x = 31
The value of the side c will be 5.56 cm and angle C is 32.49° and angle B is 42.51°.
<h3>What is law of cosine?</h3>
Let there is a triangle ABC such that |AB| = a units, |AC| = b units, and |BC| = c units and the internal angle A is of θ degrees, then we have:
a² + b² – 2ab cos C = c²
Given triangle ABC, A = 105°, a = 10 cm, b = 7 cm.
Then we have
7² + c² – (2 · 7 · c) cos 105° = 10²
c² + 3.62c – 51 = 0
On solving, we have
c = 5.56
Then the angle C will be
10² + 7² – 2 · 7 · 10 · cos C = 5.56²
149 – 140 cos C = 30.91
cos C = 0.8435
C = 32.49°
We know that
∠A + ∠B + ∠C = 180°
105° + ∠B + 32.49° = 180°
∠B = 42.51°
Learn more about law of cosines here:
brainly.com/question/17289163
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Dang that’s nice free points thank you