The Aztecs established an empire in the highlands of Guatemala
O the Valley of Mexico
O the Andes Mountains
the Amazon Rainforest

True

Explanation:

Not sure what your asking but that question is a true statement.

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°

i believe we're not a republic so that is a hard question