Refer to c^2=a^2+b^2 (^2 means squared)
C is the hypotenuse and will be the longest measure
So 15^2= 9^2+12^2
225=225
If both sides are equal then the triangle is a right triangle, if the hypotenuse (or c) is lower or higher than you can determine whether it’s obtuse or acute
It would be a right triangle
C = 3b+2d is the same as 3b+2d = C
Let's isolate d. To do this, we first need to subtract 3b from both sides
3b+2d = C
3b+2d-3b = C-3b
2d = C-3b
Then divide both sides by 2
2d = C-3b
2d/2 = (C-3b)/2
d = (C-3b)/2
Take note of the parenthesis as they are very important. We want to divide ALL of C-3b over 2. We don't want to just divide -3b over 2.
The answer choices you have aren't 100% clear but I have a feeling your teacher meant to say d = (C-3b)/2 instead of d = C-3b/2 for choice A
If that assumption is correct, then the answer is choice A.
The answer is 1500 I hope this help!
