Answer:

Step-by-step explanation:
we know that
The formula to find the sum is equal to

where
a1 is the first term
an is the last term
n is the number of terms
In this problem we have



substitute the values in the formula

Step-by-step explanation:

1. BC is 1+3=4 (units)
2. AD is 3+5= 8 (units)
3. Draw the altitude CH from point C, as shown in the figure.
4. Then triangle CHD is a right triangle, with hypothenuse CD, and sides HD and CH.
5.



6. AB=CD=4.47 because the trapezoid is isosceles.
7. P= BC+AD+AB+CD=4+8+4.47+4.47=20.9 (units)
Answer:
Cos A = 24/25, Tan A = 7/25
Step-by-step explanation:
Given that Sin A = 7/25
Sin = Opp/hyp
Therefore using Pythagoras theorem, adjacent will be;
= √(25²-7²)
= √576
= 24
Thus;
Cos A = adjacent/hypotenuse
= 24/25
Cos A = 24/25
Tan A = opp/hypotenuse
= 7/25
Tan A = 7/25
Answer:
Step-by-step explanation:
start by subtracting the original value from the reduced value.
205.67-145.90=59.77
now compare the change of rate
59.77=r(205.67)
59.77/205.67=r
r=29%