Cosine Rule again:-
cos A = (9^2 - 6^2 - 14^2) / (-2*6*14)
= 0.8988
m < A = 26 degrees
1) 3x+y+z=4
2) 2x+2y+3z=3
3) x+3y+2z = 5
1)*2 6x + 2y + 2z = 8
2) 2x + 2y +3z = 3
- __________________
4x - z = 5
2)*3 6x + 6y + 9z = 9
3)*2 2x + 6y + 4z = 10
- __________________
<span>4x+5z =-1
</span>
4x+5z = -1
4x - z =5
- ________
6z = -6
<u>z = -1
</u><u /><u>
</u>If z=-1,
4x -(-1) =5
4x = 5-1
x = 4/4
<u>x=1</u>
3x+y+z=4
3(1)+y+(-1)=4
3+y-1=4
<u>y=2
So z=-1, x=1, y=2</u>
A right angle = 90 degrees
A round angle = 360 degrees
1. 3 x 90 = 270 degrees
2. 4 x 90 = 360 degrees
3. 1 1/2 x 90 = 135 degrees
4. 2 1/3 x 90 = 210 degrees
5. 2/9 x 360 = 80 degrees
6. 3 3/8 x 360 = 1,215 degrees
Answer:
it's an right angle triangle
