Answer:
Perimeter is 17.07
Step-by-step explanation:
We know that DF = EF = 5 cm, since D and E are the midpoints of AC and AB, both of which are 10 cm in length.
We need to use the Pythagorean theorem to get the length of DE.

So the perimeter of DEF is 5 + 5 + 7.07 = 17.07
Volume of a sphere is given by the formula:

If we pull the 4 out front we have,

.
Volume of a cone is given by the formula:

Notice that if the height of the cone is equal to the radius,

then it's exactly what we see in our volume formula without the 4!
Answer:
261 km
Step-by-step explanation:
given,s=constant
d1/T1=d2/T2
d1=90km,t1=50 min
d2=? ,t2=(120+25)min
=145min
therefore,d2=(90×145)/50
=261 km
0.08 divided by 1.44 is 0.055555556
N/d = 2/3 -------------------> 3n = 2d
(n + 2)/(d + 2) = 3/4 ------> 4n + 8 = 3d + 6