Answer:
EF = 58/7
Step-by-step explanation:
If you extend both BC and AD to meet at P you get 3 similar triangles PAB, PEF, and PCD. Let's call BF = 3x and FC = 4x. Therefore the following proportions can be expressed:
BP/7 = (BP+7x)/10
10BP = 7*(BP+7x)
10BP = 7BP+49x
3BP = 49x
BP = (49/3)x
BP/7 = (BP+3x)/EF
EF = (BP+3x)*7/BP
EF = ((49/3)x + 3x)*7/((49/3)x)
EF = ((58/3)x*7*3)/(49x)
EF = 58/7
Answer:
B
Step-by-step explanation:
did the math for it!!
