A, B, C are three angles of a Triangle if A-B=25° and B-C = 10° then angle B is
Answers
Answer:
A−B=15∘ .
B−C=30∘
B=C+30∘
On adding both equation, we get
A−C=45∘
A=C+45∘
In a triangle,
A+B+C=180∘ .
Substituting the value from equation (1) and (2), we get
C+45∘+C+30∘+C=180∘
3C=105∘
∠C=35∘.
Substituting this value in equation (1) and (2), we get
∠B=65∘
∠A=80∘
Hence, the angles are ∠A=80∘ ∠B=65∘ ∠C=35∘.
SOLUTION
GIVEN
A , B , C are three angles of a Triangle
A - B = 25° and B - C = 10°
TO DETERMINE
The angle B
EVALUATION
Here it is given that A , B , C are three angles of a Triangle
So we have
A + B + C = 180° - - - - (1)
A - B = 25° - - - - - - - - (2)
B - C = 10° - - - - - - - - - (3)
Equation 2 - Equation 3 gives
A - 2B + C = 15° - - - - - (4)
From Equation 1 we get
A + C = 180° - B
From Equation 4 we get
180° - B - 2B = 15°
⇒ 3B = 165°
⇒ B = 55°
From Equation 2 we get
A = 25° + 55° = 80°
From Equation 3 we get
C = 55° - 10° = 45°
FINAL ANSWER
A = 80° , B = 55° , C = 45°
━━━━━━━━━━━━━━━━
Learn more from Brainly :-
If ∠A and ∠B are two adjacent angles of a parallelogram. If ∠A = 70°, then ∠B = ?
https://brainly.in/question/18539197
2. The measure of each angle of an equilateral triangle is
https://brainly.in/question/23122603