Question

In a diagram, ∠A and ∠B are vertical angles, and ∠B is a complementary angle with ∠C. If ∠A=22°, write an equation that you can use to solve for ∠C.

Answer 1

22° + m<C = 90°

Explanation:

Pre-Solving

We are given that <A (which is equal to 22°) and <B are vertical angles, and that <B is complementary to <C.

We want to write an equation that will help us solve <C.

Solving

Recall that vertical angles are congruent by vertical angles theorem.

This means that <A ≅ <B; it also means that the measure of <B is also 22°.

Also recall that complementary angles add up to 90°.

This means that m<B + m<C = 90°.

Since we deduced that m<B is 22°, we can substitute that value into the equation.

Hence, an equation that can be used to solve for <C is:

22° + m<C = 90°