The answer is No it is not
3pi/7 < pi/2 because 3/7 < 1/2, and pi/2 is a right angle. Conclusion: the angle opposite side a is an acute angle. In this situation the triangle could be a right triangle, in which case C would be true, but it does not have to be a right triangle, so don´t choose C. Similarly, it could be an acute triangle, in which case B would be true, but it does not have to be, so don´t choose B. Also, A says the angle opposite side a is obtuse, which is false. So don´t choose A. That leaves D, which says the angle opposite side a is acute, which we know is true. So the answer is <span>D. b^2 + c^2 > a^2</span>
<u>Given</u>
AC = BC
<u>Substitution</u>
∠1 = ∠3
<u>Base ∠'s of isosceles triangle =</u>
∠1 = ∠3
<u>Vertical angles =</u>
∠2 = ∠3
3x+4y=12
9x-2y=15
we will use elimination
multiply 3x+4y=12 by -3
-9x-12y=-36
9x-2y=15
_________ add
-14y=-21
÷-14 both sides
y=1.5
find x
3x+4 (1.5)=12
3x+6=12
-6 both sides
3x=6
÷3 both sides
x=2
x=2
y=1.5
