Answer: 
Step-by-step explanation:
A line that cuts a circle at two points is called "secant".
There is a theorem known as "Intersecting Secant Theorem". This is the theorem you need to use to find the value of "d".
According the Intersecting Secant Theorem:

Having this expression, the next step is to solve for "d":
Use Distributive property:

Subtract 256 from both sides:


Divide both sides by 16:

The value of "d" rounded to the nearest tenth is:

Answer:
x=1
Step-by-step explanation:
1.Move the constant to the right
2. Calculate
3. Divide both sides
Answer:
178.3 mm²
Explanation:
The surface area of the regular pyramid is equal to the sum of the base and lateral areas:()