Volume of a cube: V = s^3, where s is the length of the edge.
So, the sum of them will be 1^3 + 2^3 = 9
When any angle bisects with other angle then both the angles are equal.
Then, m of angle ABD = angle CBD
ABD = 70
ABD = CBD = 70°
ABC = 70 + 70 = 140°
You multiply the denominator on one side of the equation by the numerator and vice versa. So for example(S)I'm going to multiply 4 by nine and 3 times n. Then that comes out to 3n=36. After you multiply, you divide from both sides to get the variable by itself. So you would divide both sides by 3 and you're final answer would be n=13. Hope this helped!
