Answer:
a=8cm
Step-by-step explanation:
Because the triangles are similar, you can set the sides to be proportional
1. 16/16=8/a
2. If you cross multiply that mean that a=8
Answer:
B. 
Step-by-step explanation:
Let l represent length of rectangle and w represent width of rectangle.
We have been given four formulas for the perimeter of rectangle. We are asked to choose the formula that displays a common student error for finding the perimeter.
We know that perimeter of a polygon is sum of all sides of the polygon. We also know that rectangle is polygon having two sets of equal sides.
The perimeter, P, of rectangle will be sum of its all sides that is:

Combine like terms:

Factor out 2:

Upon looking at our given choices, we can see that formula represented by option B displays a common student error for finding the perimeter.
I think it’s C sorry if I’m wrong
15 miles is five times 3 miles.
It will take 40*5=200 minutes to go 15 miles.
200 minutes = 3+20/60 hours = 3hrs 20min