Triangle Angle Calculation: Finding Angle A When B=2A and C=3B

Question

B ∢B is 2 times bigger than A ∢A andC ∢C is 3 times bigger than B ∢B .

Calculate A ∢A .

AAABBBCCC3B

Video Solution

Step-by-Step Solution

To solve this problem, let's calculate A ∢A with the steps outlined below:

  • Step 1: Write the equations for each angle based on the given conditions: B=2A ∢B = 2A C=3B=3(2A)=6A ∢C = 3B = 3(2A) = 6A

  • Step 2: Use the sum of angles in a triangle: A+B+C=180 ∢A + ∢B + ∢C = 180^\circ Substitute the expressions: A+2A+6A=180 A + 2A + 6A = 180

  • Step 3: Simplify the equation: 9A=180 9A = 180 Divide both sides by 9 to solve for AA: A=1809=20 A = \frac{180}{9} = 20

Therefore, the solution to the problem is A=20 ∢A = 20^\circ .

Answer

20°