Points D, E and F are the midpoints of the sides of triangle ABC. If AD=6, CF=4 and the perimeter of triangle ABC = 30, then find BE.
2006-10-25 13:16:56 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
You have one half side (AD) that is 6, so the full side (AC) is 12
The other half side (CF) is 4 so the full side (BC) is 8
The total perimeter is 30:
Let x be the length of the unknown side (AB):
8 + 12 + x = 30
x = 10, so the half width (BE) is 5.
BE has a length of 5.
2006-10-25 13:20:20 · answer #1 · answered by Puzzling 7 · 0⤊ 1⤋
Given AD=6 & D is the midpoint of AB so
DB=6 & AB=12
Given CF=4 & F is the midpoint of AC so
AF=4 & AC=8
P=30=AB+BC+AC=12+BC+8=20+BC
BC+20=31
BC=10
Since E is the midpoint of BC, BE=BC/2=10/22=5
Answer is BE=5
2006-10-25 20:32:06 · answer #2 · answered by yupchagee 7 · 0⤊ 0⤋
Alicia, you haven't mentioned which sides D, E F are mid-points of. The picture changes drastically as you move these points around.
Assuming D, E, F are mid-points of AB, BC, CA respectively, then 2(6) + 2(4) + 2(BE) = 30.
Hence BE = 5 ... WORK IT OUT.
2006-10-25 20:23:07 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Double AD and CF, subtract them both from the perimeter, then divide the remaining number by half. Tada! Your answer.
BE=5
I hope I am correct.
2006-10-25 20:22:20 · answer #4 · answered by advgrsbsdace 2 · 0⤊ 0⤋
perimeter-2(AD) - 2(CF)=2(BE)
30-12-8=10
10/2=5
BE=5
2006-10-25 20:20:45 · answer #5 · answered by natasha b 1 · 0⤊ 0⤋
BE is 5
If AD=6, then AC=12
If AE=4 then AB+8
ABC=30
ABC- (AC+AB)=10
Therefore BE=5
2006-10-25 20:29:34 · answer #6 · answered by ijcoffin 6 · 0⤊ 0⤋