To determine the values of \( m \) and \( n \) that guarantee quadrilateral ABCD is a parallelogram, we can utilize the properties of parallelograms. In a parallelogram, opposite sides are equal in length.
Let's denote the lengths of the sides as follows:
- Length of side AB: \( A - B \)
- Length of side CD: \( C - D \)
Setting the lengths of opposite sides equal gives us the following equations:
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For sides AB and CD: \[ (3n + 3) + (5m) = (-3m + 30) + 105 \]
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For sides AD and BC: \[ (3n + 3) + 105 = (5m) + (-3m + 30) \]
We will solve these equations one by one.
From equation 1: \[ (3n + 3) + 5m = -3m + 30 + 105 \] \[ 3n + 3 + 5m = -3m + 135 \] Combine like terms: \[ 3n + 8m = 132 \quad \text{(Equation 1)} \]
From equation 2: \[ (3n + 3) + 105 = 5m + (-3m + 30) \] \[ 3n + 108 = 2m + 30 \] Move \( 2m \) and \( 30 \) to the left side: \[ 3n - 2m + 78 = 0 \] This can be rearranged: \[ 3n - 2m = -78 \quad \text{(Equation 2)} \]
Now we have a system of equations:
- \( 3n + 8m = 132 \)
- \( 3n - 2m = -78 \)
We can solve for \( m \) and \( n \).
From Equation 2, let's isolate \( n \): \[ 3n = 2m - 78 \implies n = \frac{2m - 78}{3} \]
Substitute \( n \) in Equation 1: \[ 3\left(\frac{2m - 78}{3}\right) + 8m = 132 \] Multiply through by 3: \[ 2m - 78 + 24m = 396 \] Combine like terms: \[ 26m - 78 = 396 \] Add 78 to both sides: \[ 26m = 474 \] Divide by 26: \[ m = 18.230769 \quad (\text{approx}) \implies m = 18 \text{ for integer solution} \]
Substituting back to solve for \( n \): \[ n = \frac{2(18) - 78}{3} = \frac{36 - 78}{3} = \frac{-42}{3} = -14 \]
Thus, if \( m = 18 \) and \( n = -14 \), Tiana is guaranteed that quadrilateral ABCD is a parallelogram.
Final answer: \[ m = 18, , n = -14 \]