Question

use the following diagram to complete the required information.
m∠ros = 20 deg 15 40, m∠sot = 10° 12 30
m∠rot=
31° 28 10
30° 28 10
30° 27 10

Explanation:

Step1: Add degrees

$20^{\circ}+ 10^{\circ}=30^{\circ}$

Step2: Add minutes

$15'+12' = 27'$

Step3: Add seconds

$40''+30''=70''$
Since $60'' = 1'$, $70''=1'10''$

Step4: Adjust minutes

Add the extra minute from seconds to minutes: $27'+1'=28'$

Step5: Combine results

$\angle ROT=\angle ROS+\angle SOT = 30^{\circ}28'10''$

Answer:

$30^{\circ}28'10''$ (the second option)