I'm pretty sure both B and C equal 12 as well
Since the triangle equals 180 and the angels are all congruent
(1/2)x+b=y because the equation that given the slope is 1/2 if you leave y alone and take the x’s number
put the point now , 4+b=3 so b is -1
the equation is (1/2)x-1=y
Answer:
Part A) The triangles ABC and EDC are similar by AAA, because the three internal angles are equal in both triangles
Part B) The width of the river is about 
Step-by-step explanation:
we know that
If two triangles are similar, then the ratio of its corresponding sides is equal and its corresponding angles are congruent
Part A) we know that
In this problem , triangles ABC and CDE are similar by AAA, because its corresponding angles are congruent
so
m<DCE=m<ACB -----> by vertical angles
m<EDC=m<ABC -----> is a right angle
m<DEC=m<CAB -----> the sum of the internal angles must be equal to 180 degrees
Part B) we know that
The triangles ABC and EDC are similar -------> see Part A
therefore

substitute the values and solve for AB


So the formula for the area of a triangle is
(b = base, h = height). In this case, by counting from (-3,-3) to (-3,2) the height is 5 and the base is 4 counting from (-3,2) to (1,2).
Using this info, we can form the equation
and solve from there.
