Question

1. 12) 13) 14)

Explanation:

Step1: Analyze problem 13

Since there is no information about the congruence or similarity of the triangles in problem 13, we cannot establish an equation to solve for \(x\).

Step2: Analyze problem 14

In problem 14, because the two sides of the large triangle are equal (marked with the same tick - marks), the triangle is isosceles. And the line segment divides the base into two parts. We can set up the equation \(12=2x - 12\) (because in an isosceles triangle, the perpendicular from the vertex to the base bisects the base).
Solve the equation \(12=2x - 12\):
Add 12 to both sides: \(12 + 12=2x\), so \(24 = 2x\).
Divide both sides by 2: \(x = 12\).

Answer:

For problem 13: Cannot be determined.
For problem 14: \(x = 12\)