Answer:
A = 10.27cm²
Step-by-step explanation:
Let's represent the width as x,
therefore since the length is 4 more than 3 times the width, it can be represent as 3x + 4, Perimeter = 18.4cm
Perimeter of a rectangle = 2(L + B)

width = 1.3cm
Length = 3x + 4 = 3*1.3 + 4 = 7.9cm
Area of a rectangle = length x width
A = 7.9 * 1.3 = 10.27cm²
B. (k+10f)(k-5f) you can tell in 2 ways. 1. if the second sign is neg then the signs in the factors are going to be one neg and one positive so that knocks out C and D. Then you look at the second term and since the 5 is positive then the 10 has to be positive so you end up with a positive 5kf.
The second way is to FOIL them out. When you check B you get

combine your like terms and you have your original expression of

Hope that helps
Answer:
D to C
Step-by-step explanation:
The radius is half the diameter or the center point to the edge (circumference)
Let the length of one of the diagonals be 2x and the other be 2y, then
cos (76/2) = x/10
x = 10 cos 38 = 7.88 cm
sin (76/2) = y/10
y = 10 sin 38 = 6.16 cm