Answer:
$< abc = < ebc \\ < acb = < ecd \\ if \: two \: angles \: in \: the \:two \: different \: triangles \: are \: equal \: then \: the \: third \: angle \: in \: the \: triangle\: must \: be \: equal. \\ using \: pythogres \: theorum \\ ab = \sqrt( ac ^{2} - bc^{2} )\\ = \sqrt (15 ^{2} - 12 ^{2}) \\ = \sqrt( 225 - 144 )\\ = \sqrt(81) \\ ab = 9 \\ sides \: of \: similar \: triangle \: are \: propotional \\ ac \div ec = dc \div bc \\ 15 \div x = 12 \div 6\\ x = 15 \times 6\div 12\\ x = 15 \div 2 \\ x = 7.5 \\ so \: ec \: = 7.5 \\ you \: can \: check \: this \: by \: applying \: pythogores \: theorum. \\ i \: hope \: this \: helps$

8 0

2 years ago

vazorg [7]

Answer:

x=106 degrees

Step-by-step explanation:

The two opposite angles in a parallelogram are always the same and we know 360 degrees in a parallelogram.

x+x+74+74=360.

2x+148=360

2x=212

x=106 degrees

4 0

3 years ago

podryga [215]

5+2x=11 (this is the equation)
-5 -5 
2x=6 (this is the answer)
x=3

5 0

3 years ago