Answer: D.
Step-by-step explanation:
In the given figure, we have an obtuse triangle which has sides a, b, and c, and the angle opposite the side of length b is obtuse.
∵ In a triangle, the side opposite to the largest angle is largest.
Thus, the largest side in then given obtuse triangle= c
The Pythagorean inequalities theorem says that If a triangle is obtuse than the square of the largest side is greater than the sum of square of other two sides.
Therefore, we have

B and C for the first two
Answer:
D) -0.87
Step-by-step explanation:
I took this test don't quote me on the answer but this is what my peers put.
Answer:
b=12
Step-by-step explanation:
a^2+b^2=c^2
(9×9) + b^2= 15×15
81+ b^2= 225
-81. -81
b^2=144
√. √
b= 12