∠ACB and ∠BCD are supplementary angles. The angles have the following measures: ∡ACB=(x+28)° and ∡BCD=(x+48)° . What is m∠BCD ?

1 answer

Since angles \( \angle ACB \) and \( \angle BCD \) are supplementary, their measures add up to \( 180^\circ \). Therefore, we can set up the equation:

\[ \angle ACB + \angle BCD = 180^\circ \]

Substituting the expressions for the angles:

\[ (x + 28) + (x + 48) = 180 \]

Combining like terms gives:

\[ 2x + 76 = 180 \]

Next, we solve for \( x \) by subtracting \( 76 \) from both sides:

\[ 2x = 180 - 76 \] \[ 2x = 104 \]

Now, divide by \( 2 \):

\[ x = 52 \]

Now that we have the value of \( x \), we can find the measure of \( \angle BCD \):

\[ \angle BCD = x + 48 = 52 + 48 = 100^\circ \]

So, the measure of \( \angle BCD \) is

\[ \boxed{100^\circ} \]