To find the measure of angle $\angle ACB$, we need to determine the measures of the other two angles inside triangle $ABC$ first.
Step 1: Find the measure of angle $\angle BAC$.
Points $D$, $A$, and $C$ lie on a straight line. This means that angle $\angle DAB$ and angle $\angle BAC$ form a linear pair, so they add up to $180^\circ$.
We are given:
$\angle DAB = 132^\circ$
So, we can calculate $\angle BAC$:
$$ \angle BAC = 180^\circ - 132^\circ $$
$$ \angle BAC = 48^\circ $$
Step 2: Use the sum of angles in a triangle.
The sum of the interior angles of any triangle is always $180^\circ$. For triangle $ABC$, this means:
$$ \angle ABC + \angle BAC + \angle ACB = 180^\circ $$
We know:
- $\angle ABC = 67^\circ$ (given)
- $\angle BAC = 48^\circ$ (calculated in Step 1)
Substitute these values into the equation:
$$ 67^\circ + 48^\circ + \angle ACB = 180^\circ $$
Step 3: Solve for $\angle ACB$.
First, add the known angles together:
$$ 67 + 48 = 115 $$
So, the equation becomes:
$$ 115^\circ + \angle ACB = 180^\circ $$
Now, subtract $115^\circ$ from $180^\circ$:
$$ \angle ACB = 180^\circ - 115^\circ $$
$$ \angle ACB = 65^\circ $$
Final Answer:
65°
Parent Tip: Review the logic above to help your child master the concept of triangle angle measures.