We can make a drawing to see better:
7) We know that RM = 4 and MS = 9, so:
[tex]\begin{gathered} \tan a=\frac{MS}{RM}=\frac{TM}{MS} \\ TM=\frac{MS^2}{RM}=\frac{9^2}{4}=\frac{81}{4}=20.25 \end{gathered}[/tex]
The answer is TM = 20.25
8) We know that RS = 20 and RM = 8, so:
[tex]\begin{gathered} \sin b=\frac{RM}{RS}=\frac{RS}{RT} \\ RT=\frac{RS^2}{RM}=\frac{20^2}{8}=\frac{400}{8}=50 \end{gathered}[/tex]
The answer is RT = 50.
9) We know that RM = 5 and MS = 7, so:
[tex]\begin{gathered} \tan b=\frac{RM}{MS}=\frac{RS}{TS} \\ TS=RS\cdot\frac{MS}{RM} \\ RS=\sqrt[]{RM^2+MS^2} \\ TS=\sqrt[]{RM^2+MS^2}\cdot\frac{MS}{RM} \\ TS=\sqrt[]{5^2+7^2}\cdot\frac{7}{5}=\sqrt[]{25+49}\cdot\frac{7}{5} \\ TS=\sqrt[]{74}\cdot\frac{7}{5}\approx12.043 \end{gathered}[/tex]
The answer is TS = 12.043
10) We know that RM = 1/2 and MS = 1/4, so:
[tex]\begin{gathered} \sin b=\frac{RM}{RS}=\frac{RS}{RT} \\ RT=\frac{RS^2}{RM}=\frac{RM^2+MS^2}{RM} \\ RT=\frac{(\frac{1}{2})^2+(\frac{1}{4})^2}{\frac{1}{2}}=2\cdot(\frac{1}{4}+\frac{1}{16}) \\ RT=2\cdot\frac{4+1}{16}=\frac{5}{8}=0.625 \end{gathered}[/tex]
The answer is RT = 5/8 = 0.625