Oblique Triangle

What is the correct formula to find the lenght of AC by using Sine Rule?

• $\frac{\sin\ 51.3}{81\degree}=\frac{\sin\ AC}{85\degree}$

• $\frac{51.3}{\sin\ 81\degree}=\frac{\sin\ 85\degree}{AC}$

• $\frac{51.3}{\sin\ 81\degree}=\frac{AC}{\sin\ 85\degree}$

• $\frac{51.3}{\sin\ 85\degree}=\frac{AC}{\sin\ 81\degree}$

Calculate the lenght of AC.

• 51.74 cm

• 57.14 cm

• 54.17 cm

• 75.14 cm

What is the correct formula to find thae angle of P?

• $\frac{\sin\ x\degree}{\sin\ 40\degree}=\frac{10}{7}$

• $\frac{7}{\sin\ x\degree}=\frac{10}{\sin\ 40\degree}$

• $\frac{7}{\sin\ x\degree}=\frac{\sin\ 40\degree}{10}$

• $\frac{\sin\ x\degree}{10}=\frac{\sin\ 40\degree}{7}$

Calculate the angle of  $\angle QPR$  .

•  $66.67\degree$  

•  $67.67\degree$  

•  $76.67\degree$  

•  $76.76\degree$  

Which of the following the correct formula to find the length of AB?

• $b^2=a^2+c^2-2ab\ \cos\ B$

• $c^2=a^2+b^2-2ab\ \cos\ C$

• $c^2=a^2+b^2-2ab\ \cos\ B$

• $b^2=a^2+c^2-2ac\ \cos\ C$

Find the length of PR by using Cosine Rule.

• $PR^2=9.2+8.5-\left(9.2\right)\left(8.5\right)\cos\ 89\degree$

• $PR^2=9.2^2+8.5^2-\left(9.2\right)^2\left(8.5\right)^2\cos\ 89\degree$

• $PR^2=9.2^2+8.5^2-2\left(9.2\right)\left(8.5\right)\cos\ 89\degree$

• $PR^2=9.2^2+8.5^2+2\left(9.2\right)\left(8.5\right)\cos\ 89\degree$

Evaluate the length of PR.

• 4.04 cm

• 7.08 cm

• 12.42 cm

• 12.63 cm

What is the correct formula to find the area of ABC.

• $\frac{1}{2}\left(15+12\right)\sin\ 68\degree$

• $\frac{1}{2}\left(15+12\right)\cos\ 68\degree$

• $\frac{1}{2}\left(15\right)\left(12\right)\sin\ 68\degree$

• $\frac{1}{2}\left(15\right)\left(12\right)\cos\ 68\degree$

Calculate the area of ABC.

• $83.45\ cm^2$

• $33.71\ cm^2$

• $5.06\ cm^2$

• $12.52\ cm^2$

Find the area for $\Delta$ ABC .

•  $73.53\ cm^2$  

•  $75.33\ cm^2$  

•  $202.03\ cm^2$  

•  $220.30\ cm^2$