69% is the same as .69, which is the same as 69/100
m∠R = 27.03°
Solution:
Given In ΔQRP, p = 28 km, q = 17 km, r = 15 km
To find the measure of angle R:
Law of cosine formula for ΔQRP:

Substitute the given values in the above formula.



Switch the given equation.

Subtract 1073 from both side of the equation.

Divide by –952 on both sides.



Hence m∠R = 27.03°.
i would just round 9.3 to 9 and 4.4 to 4 so i subtract 9-4 so that equals 5 so about a 5 mile diffrence
Evaporation, Solid-State Diffusion, and lastly, When Hot Water cools. <span />