Answer:
Step-by-step explanation:
an=4=a1+(n-1)*d=0.25+(n-1)*d
so (n-1)*d=4-0.25=3.75
Sn=a1*n+(n-1)*d
a1*n+3.75=8.5
0.25*n+3.75=8.5
-3.75 -3.75
0.25*n=8.5-3.75=4.75
n=4.75:0.25
n=19
so a19=a1+(19-1)*d=4
0.25+18*d=4
-0.25 -0.25
18*d=3.75
d=3.75/18
d=0.208
so a2=a1+0.208=0.25+0.208=0.458
a2=0.458
Element of Circle
the central angle (α) = (the length of the arc x 360°)/2πr (r = radius)

convert to rad:

Answer: the awnser is 9, 40, 41 mark me brainlist
Step-by-step explanation:
Sum of the squares of the two side = Square of longest side
a² + b² = c²
a)
So let's check 7, 24, 25
Is 7² + 24² = 25² ?
7*7 + 24*24
49 + 576
=625.
Let us perform the other side 25²
25² = 25 * 25 = 625
Therefore the left hand side = Right hand side.
Therefore 7, 24, 25 is a Pythagorean Triple
b)
Let's check 9, 40, 41
Is 9² + 40² = 41² ?
9² + 40²
9*9+ 40*40
81 + 1600
=1681
Let us perform the other side 41²
41² = 41 * 41 = 1681
Therefore the left hand side = Right hand side.
Therefore 9, 40, 41 is a Pythagorean Triple.
Read more on Brainly.com - brainly.com/question/1471164#readmore
This is the answer i supposed fot
Let the present age of student be x
Present of teacher will be 4x
After 20 years,
Age of student = x + 20
Age of teacher = 4x + 20
According to the given condition after 20 years,
x + 20 = (4x + 20)/2
x + 20 = 2x + 10
2x - x = 20 - 10
x = 10
So student's present age is 10 years while teacher's is 4 x 10 i.e 40 years.
Hope This Helps You!