Answer:
Rhombus
Step-by-step explanation:
Let the equal sides of the isosceles Δ ABC be x.
Given that the perimeter of Δ ABC = 50m.
Therefore, 2x + AC = 50 --- (1)
It is also given that the perimeter of Δ ABD = 40m.
Therefore, x + BD + AD = 40
BD is the median of the Δ ABC. Therefore, D is the midpoint of AC.
So AD = CD.
Or, AD =
AC
Therefore, 
Multiply both sides by 2.
2x + 2BD + AC = 80
From (1), 2x + AC = 50.
Therefore, 2BD + 50 = 80
2BD = 80 - 50
2BD = 30
BD = 15m.
Yes pi, which letter please?7th grade is not an average
Answer:
Step-by-step explanation:
surface area=area of sides +area of top and bottom
=2(4+5)×8+2×(4×5)
=2[(9×8)+20]
=2[72+20]
=2×92
=184 m²
Answer:
ED = 12 and FD = 24
Step-by-step explanation:
See the attached diagram.
The perpendicular distance between the three parallel lines are same i.e. AB = BC = 8
Therefore, the parallel lines will divide any transverse line ( say FD ) in 1 : 1 ratio i.e. will divide equally.
Therefore, FE = ED = 12 units.
Again, FD = FE + ED = 12 + 12 = 24 units. (Answer)