Question

Look at the two triangular flags below.



What is the length of the side BC of triangle ABC?
Answer
A)2 m
B)3 m
C)6 m
D)9 m

Answer 1

Triangle ABC is congruent to triangle DEF


So BC is congruent to EF, which means


x-1 = 3x-7


Solve for x:


x-1 = 3x-7

x-3x = -7+1

-2x = -6

x = -6/(-2)

x = 3


----------

BC = x-1

BC = 3-1

BC = 2


So BC is 2 meters long

Answer 2

The two triangles are congruent by angle-angle-side congruency. Hence BC=EF so x=3 and hence BC=2