Exercise 25 Page 104

Two angles are supplementary if the sum of their measures is 180^(∘). Since we are told that ∠3 is a supplement of ∠2, we can create an equation to demonstrate this relationship. m∠ 3 + m∠ 2= 180^(∘) We can find m∠ 3 by substituting the given value, m∠2=147^(∘), into the equation.

m∠ 3 + m∠ 2= 180^(∘)

Substitute

m∠ 2= 147^(∘)

m∠ 3 + 147^(∘) = 180^(∘)

SubEqn

LHS-147^(∘)=RHS-147^(∘)

m∠ 3= 33^(∘)

The measure of m∠ 3 is 33^(∘).