I think you can use cosine rule if only the lines that form the <52 are equal.
Answer:
50%
Step-by-step explanation:
TRUST
First, you know that the slope will be the same (3/2).
Plug in the points 0 for x and 7 for y in order to find b.
7=3/2*0+b
b=7
Then put the new slope and y-intercept into the equation:
y=3/2x+7
First isolate 
by subtracting 1 from both sides of the equation.
That gives you 
.
From here, since x is being divided by 2, multiply both sides of the equation by 2.
So <em>x = 10</em>.
Work is attached in the image below.
Equilateral = all sides are same
side length = 8 3/4 ÷ 3
= 35/4 ÷ 3
= 35/4 × 1/3
= 35/12
