Question

Use the diagram to complete the statement.-74A 3G B530)45°C С412/F9ECBC=

Answer 1

sin 45 = 4/BC

`\begin{gathered} \frac{1}{\sqrt[]{2}}\text{ = }(4)/(BC) \\ \text{cross}-\text{ multiply,} \\ BC\text{ = 4 }\sqrt[]{2} \end{gathered}`

`\begin{gathered} \cos \text{ 45 = }\frac{DF}{12\sqrt[]{2}} \\ \\ \frac{1}{\sqrt[]{2}}\text{ = }\frac{DF}{12\sqrt[]{2}} \\ DF\text{ = 12} \\ FE\text{ = 9} \\ DE\text{ = DF + FE = 12 + 9 = 21} \\ DE\text{ =21} \end{gathered}`