Answer:
do you need it to be simplified?
Perimeter is adding the 3 sides together. Since both triangles have the same perimeter set both triangles to equal:
(x+3 + x+3 + x+3) = (x+3 + 2x-3 + x)
Simplify each side:
3x+9 = 4x
Subtract 3x from each side:
x=9
Answer:
x=122°
Step-by-step explanation:
sum of all interior angles in a quadrilateral = 360°
then ,
119+105+78+m = 360
m = 58
....
m+ x = 180 ( linear pair)
58+x = 180
x = 122
A OK this was hard very hard
