The walls are vertical so the angle opposite X would be a right angle which is 90 degrees.
X would be 180 - 90 - 35 = 55 degrees
X and 2y - 5 are complementary angles which add together to equal 90:
2y - 5 + 55 = 90
Simplify:
2y +50 = 90
Subtract 50 from both sides:
2y = 40
Divide both sides by 2:
y = 20
Divide the sides of the larger triangle by the corresponding side of the smaller one:
18/7.2 = 2.5
Figure A is 2.5 times the size of figure B
The scale factor is 2.5
