Find Unknown Angle

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

Give your answer correct to 1 decimal place.

Answer explanation

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

$\sin\left(x\right)\ =\ \frac{6.5}{9.6}$

$x\ =\ \sin^{-1}\left(\frac{6.5}{9.6}\right)$


$x\ =42.61614271$

$x\ =\ 42.6\degree\ \left(1\ dp\right)$

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

Give your answer correct to 1 decimal place.

Answer explanation

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

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

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


$x\ =24.74652459$

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

What is the measure of the missing angle?

• 76

• 86

• 166

• 156