Set up a proportion.
2/3 = 12/x. Cross multiply the proportion.
2x = 36. Solve for x.
x = 18.
A. An obtuse angle is less than 180 but greater than 90. So for examples sake I will use 179 degrees. 179 divided by 2 (as the angles are congruent) = 89.5 which is less than a right angle. Therefore, the angles will be acute.
Hope it helps :)
9(2w−y)=21w−9y
First you multiply the numbers in the parenthesis by 9

subtract. 21w-18w=3w

add. -9y+9y=0

divide.

Final answer is 0.
<span>0.950. Hope this helps. :)</span>