Answer:
2. ASA can be used with the definition of an isosceles triangle
3. x = 5 5/6
Step-by-step explanation:
2.
Using the given information, the definition of an isosceles triangle tells us, ...
∠A = ∠C and ∠A = ∠ABM and ∠C = ∠CBN
By substitution, ∠ABM = ∠CBN. This lets us declare ΔAMB ≅ ΔCNB by ASA, where the sides between the angles are AB and CB.
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3.
If the angles of interest are the same, then the triangles are similar. That means corresponding sides have the same ratio:
AB/AD = CB/CE
x/7 = (10-x)/5
5x = 7(10 -x) = 70 -7x . . . . . multiply by 35, simplify
12x = 70 . . . . . . . . . . . add 7x
x = 70/12 = 35/6
x = 5 5/6
