Answer:
m∠C = 90°
Step-by-step explanation:
Triangle BDC is a right triangle with the measure of angle D = 90°
By applying Cosine rule in the given triangle,
Since, Cosine of any angle in a right triangle is a ratio of Its adjacent side and Hypotenuse (Opposite side of the right angle)
CosC = [tex]\frac{\text{Adjacent side}}{\text{Hypotenuse}}[/tex]
CosC = [tex]\frac{\text{DC}}{\text{BC}}[/tex]
CosC = [tex]\frac{7}{8}[/tex]
[tex]C=\text{Cos}^{-1}(\frac{7}{8})[/tex]
C = 28.955
C = 29°
Therefore, m∠C = 29° will be the answer.
