Question

∠A and ∠B are vertical angles. If m∠A=(7x-20)° and m∠B=(6x-1)°,then find the measure of ∠A.

Answer 1

Answer: The measure of angle A is 113°

Explanation:

7x - 20 = 6x -1

+20 +20

7x = 6x + 19

-6x -6x

1x = 19

x = 19

7(19) -20 = 113

6(19) - 1 = 113

Answer 2

It's important to understand that vertical angles are always ≅.

So we can say that the m<A = m<B.

So we can setup the equation 7x - 20 = 6x - 1.

Start by subtracting 6x from both sides and we have x - 20 = -1.

Now add 20 to both sides to get x = 19.

If x = 19, then the m<A is 7(19) - 20 or 133 - 20 which is 113.