Answer:
-a to the third power is 27
-b to the second power is 16.
Step-by-step explanation:
-1 times (-3) is 3. And 3 to the 3rd power is 27.
-1 times (-4) is 4. And 4 to the 2nd power is 16.
Answer:
Step-by-step explanation:
surface area=2×1/2×10×12+2×1/2×2×13+10×2
=120+26+20
=166 square units
It should be D. Because the equation is 2(width+ height + length
9514 1404 393
Answer:
obtuse
Step-by-step explanation:
The law of cosines tells you ...
b² = a² +c² -2ac·cos(B)
Substituting for a²+c² using the given equation, we have ...
b² = b²·cos(B)² -2ac·cos(B)
We can subtract b² to get a quadratic in standard form for cos(B).
b²·cos(B)² -2ac·cos(B) -b² = 0
Solving this using the quadratic formula gives ...

The fraction ac/b² is always positive, so the term on the right (the square root) is always greater than 1. The value of cos(B) cannot be greater than 1, so the only viable value for cos(B) is ...

The value of the radical is necessarily greater than ac/b², so cos(B) is necessarily negative. When cos(B) < 0, B > 90°. The triangle is obtuse.