| Formula for the volume of a cone: 
1.b
2.c
3.b
i am truly sorry if im wrong.
Answer : Square root of 21 , -4 2/3, -30/7 , -31/6 .
Explanation :
-4 2/3 = -10/3 = -3.3333
Square root of 21 = 4.58258
-31/6 = -5.1666
-30/7 = 4.2857
And arrange them from greatest to least and there we have the answer.
Hope this helps you understand !!!!
30°, 70°, and 80°.
It is an acute-angled triangle.
Explanation:
The ratio of the measures of ∠s in Δ is 3:7:8.
So, let us suppose that the measures are, 3k, 7k, 8k.
Evidently, their sum is
180°.
3k+7k+8k=180
18k=180
k= 10
Hence, the measures are,
30°, 70°, and 80°.
As all the angles are acute, so is the triangle.