Step-by-step explanation:
there are 2 similar triangles : ABE and DCE
that means they have the same angles, and the scaling factor from one triangle to the other is the same for every side.
and that means that
DE/AE = EC/BE (= DC/AB)
we know that
AE = AD + DE
BE = BC + EC
a.
so, we have actually
DE/(AD+DE) = EC/(BC+EC)
DE/(10+DE) = 8/(2+8) = 8/10 = 4/5
DE = 4(10+DE)/5
5DE = 4(10+DE) = 40 + 4DE
DE = 40 cm
b.
AD/DE = 3/5
BC/EC must be 3/5 too.
15/EC = 3/5
15 = 3EC/5
75 = 3EC
EC = 25 cm
The perimeter of a parallelgram is the sum of the lengths of its four sides.
Parallelogram ABCD has sides AB, BC, CD, and AB.
Sides AB and CD are parallel and of equal length = 19 units.
Sides BC and CD are parallel and of equal length. Assuming thi is the length of 5 units given in the statement, the perimeter of the parallelogram ABCD is: 19 units + 19 units + 5 units + 5 units = 48 units.
Please, inform if the length of 5 units corresponds to other distance, but even in that case, with this explanation you should be able to calculate the perimeter of this and other parallelograms.
Answer: 48 untis.
Answer:
r=40% or .4
Step-by-step explanation:
32=16(1+r)^2
Answer: -x^2 + 15x
Step-by-step explanation:
