D = 25 ft is the length of a shadow. L - the length of a tree.
Two angles are 85° and 65° and the third is 180° - ( 65° + 85° ) =
= 180° - 150° = 30°.
We will use the Sine Law:
25 / sin 30° = L / sin 65°
25 / 0.5 = L / 0.9063
25 * 0.9063 = 0.5 L
22.6577 = 0.5 L
L = 22.6577 : 0.5
L = 45.3 ft.
Answer: the approximate length of the tree is 45.3 ft.
To represent this scenario, you will look at what is happening mathematically and represent it.
Beginning with 5, this will double each day, so 5 x 2 is the deposit.
Then, this amount will double, so (5 x 2) x 2 is the deposit.
Next this will double, and so on.
What is happening is that it is always doubling the previous day's deposit, so x 2 x 2 x 2, etc... you will use exponents to show the number of days that it doubled.
y = 5 x 2^x
Answer - to solve for the equivalent equation of r you would need to use the formula r=c/pi2.