What was the importance of the truman doctrine?
a. it sought to contain the spread of communism.
b. it strengthen relations between the united states and china.
c. it allowed the soviet union to develop nuclear weapons.
d. it prohibited all countries from expanding their nuclear weapons.

it sought to contain the spread of communism.

angle a = 40.6°

step-by-step explanation:

for any right angle triangle we know the pythagoras theorem reveals

hypotenuse² = height²+base²

by this formula we will calculate the length of hypotenuse

h² = 6²+7²

⇒ h =√36+49 = √85 = 9.22

now from the given triangle sin a = height/ hypotenuse

                                                sin a = 6/9.22 = 0.651

therefore

so angle a = 40.6°

they united the colonies in their fight against the british.