Sine Ratio

What is the correct equation to solve for x?

• tan (45) = x/13

• cos (45) = x/13

• sin (45) = 13/x

• sin (45) = x/13

Solve for x. Round to the nearest tenth.

• 7.5

• 34.1

• 14.1

• 18.9
• 19.5
• 47
• 27.5

What is the length of side x?

• 6.57 cm

• 7 cm

• 7.44 cm

• 26.33 cm

Which side is opposite angle x?

• 1

• 2

• 3

Calculate, in degrees, the size of the marked unknown angle.

Give your answer correct to 1 decimal place.

Answer explanation

$Sin\left(x\right)\ =\ \frac{Opp}{Hyp}$

$\sin\left(x\right)\ =\ \frac{7}{12}$

$x\ =\ \sin^{-1}\left(\frac{7}{12}\right)$


$x\ =35.68533471$

$x\ =\ 35.7\degree\ \left(1\ dp\right)$

Calculate, in degrees, the size of the marked unknown angle.

Give your answer correct to 1 decimal place.

Answer explanation

$Sin\left(x\right)\ =\ \frac{Opp}{Hyp}$

$\sin\left(x\right)\ =\ \frac{6}{9}$

$x\ =\ \sin^{-1}\left(\frac{6}{9}\right)$


$x\ =41.8103149$

$x\ =\ 41.8\degree\ \left(1\ dp\right)$

Calculate, in degrees, the size of the marked unknown angle.

Give your answer correct to 1 decimal place.

Answer explanation

$Sin\left(x\right)\ =\ \frac{Opp}{Hyp}$

$\sin\left(x\right)\ =\ \frac{3}{12}$

$x\ =\ \sin^{-1}\left(\frac{3}{12}\right)$


$x\ =14.47751219$

$x\ =\ 14.5\degree\ \left(1\ dp\right)$

Calculate, in degrees, the size of the marked unknown angle.

Give your answer correct to 1 decimal place.

Answer explanation

$Sin\left(x\right)\ =\ \frac{Opp}{Hyp}$

$\sin\left(x\right)\ =\ \frac{1.8}{4.3}$

$x\ =\ \sin^{-1}\left(\frac{1.8}{4.3}\right)$


$x\ =24.74652459$

$x\ =\ 24.7\degree\ \left(1\ dp\right)$

Calculate, in degrees, the size of the marked unknown angle.

Give your answer correct to 1 decimal place.

Answer explanation

 $Sin\left(x\right)\ =\ \frac{Opp}{Hyp}$  

 $\sin\left(x\right)\ =\ \frac{8}{14}$  

 $x\ =\ \sin^{-1}\left(\frac{8}{14}\right)$  


 $x\ =\ 34.84990458$  

 $x\ =\ 34.8\degree\ \left(1\ dp\right)$