The sum of a geometric sequence is:
s(n)=a(1-r^n)/(1-r), a=initial term and r=common ration so
s(n)=20(1-0.25^n)/(1-0.25)
s(5)=20(1-0.25^5)/(0.75)
s(5)=26.640625
Answer:
28
Step-by-step explanation:
Answer:
Length of DE is 25.
Step-by-step explanation:
Right, so this is something called midsegment theorem. ΔDBE is similar (but not congruent) to ΔABC because of the angles they share. Since DE is described as a midsegment, this means BE=EC and BD=DA; so ΔDBE is half the size of ΔABC, meaning its side lengths are also half that of the larger triangle.
(Sorry if this information was unnecessary. Just got an answer deleted because I wasn't detailed enough.)
If you take 10*9 that is 90. If all the sides are 90, then you do 90*90 and that equals 8,100
