Question #7359c

1 Answer
May 26, 2017

B(5,8)(5,8)
C(15,4)(15,4)
D(15,5/2)(15,52)

Explanation:

(1)(1) Finding B.
Slope of AEAE.
(6-4)/(-1-3)=-1/26413=12

Since AEAE is perpendicular to EBEB, the slope of BEBE is 22 (negative reciprocal of -1/212).

The (x, y)(x,y) in here will be B's coordinates.
"Slope of BE"(2)=(y-4)/(x-3)Slope of BE(2)=y4x3
2x-6=y-42x6=y4
2x-y=22xy=2

"Slope of AB"(1/3)=(y-6)/(x+1)Slope of AB(13)=y6x+1
x+1=3y-18x+1=3y18
x-3y=-19x3y=19

Solve the system of equations:
2x-y=22xy=2
-2x+6y=382x+6y=38

5y=405y=40
y=8,x=5y=8,x=5

Thus B(5,8)(5,8).

(2)(2)

The height of Triangle EBCEBC is the difference of yy coordinates of BB and EE.
Which is 8-4=484=4

The base of the Triangle is the difference of the xx coordinates of EE and CC
(The xx coordinate of CC is unkown.)
Which is (x-3)(x3).

Use the area of triangle area of EBCEBC.
EBC=1/2(x-3)(4)EBC=12(x3)(4)
24=2x-624=2x6
x=15x=15

Thus C(15,4)(15,4)

(3)(3) Finding D.
The slope of AE is the same as AD.
Thus:
AE=(y-4)/(x-3)AE=y4x3
-1/2=(y-4)/(x-3)12=y4x3

But the xx coordinate of C is the same as D.
-1/2=(y-4)/(15-12)12=y41512
-3=2y-83=2y8
y=5/2y=52

Thus: D(15,5/2)(15,52)