Given that the triangle ABC is equal to the triangle def, ab = 3, AC = 6, if the perimeter of the triangle DEF is even, find the length of EF

Given that the triangle ABC is equal to the triangle def, ab = 3, AC = 6, if the perimeter of the triangle DEF is even, find the length of EF

Because △ ABC = △ def;
So AB = De, AC = DF, BC = EF;
There are also: | AC ab|

In triangle ABC, AE = 0.2ac, AF = 0.5ab, DC = 3bd, the area of triangle EFD is 70cm 2, find the triangle ABC surface

∵AE=0.2AC,AF=0.5AB,DC=3BD∴S△AEF=1/5S△AFC=1/10S△ABCS△EDC=4/5S△ADC=1/4X1/5S△ABC=1/5S△ABCS△BDF=1/2S△ABD=1/2X3/4S△ABC∵S△DEF=S△ABC-S△BDF-S△EDC-S△AEF=13/40S△ABC=70∴S△ABC=2800/13....

Divide the base of triangle ABC into four parts, D is the middle point of BC. Given that the area of triangle EFD is 1 square decimeter, find the area of triangle ABC

Let the height of triangle EDF be H
Because D is the midpoint of BC, the height of triangle EDF is 2h, and AE = EF = FG = GB
So the area of triangle ABC is equal to:
4EF*2h/2=8*EFh/2,
EFH / 2 is just the area of triangle EDF, which is equal to 1 square decimeter
The area of triangle ABC is equal to 8 square decimeters

In known triangle ABC, AE bisector angle BAC, angle c > angle B, f is the point on AE, FD is perpendicular to BC and D, try to deduce the relationship between angle EFD, angle B and angle C

FED=B+A/2
So B + A / 2 + EFD = 90 degree
And a + B + C = 180 degree
So B + fed = C