The-points-A-B-C-have-coordinates-3-1-1-5-5-7-a-find-the-line-l-1-joining-the-points-A-and-B-b-Find-the-line-l-2-perpendicular-to-l-1-and-passes-through-the-point-B-c-show-that-the-point-C-

Question Number 35208 by Rio Mike last updated on 16/May/18

T h e p o i n t s A, B, C h a v e c o o r d i n a t e s

(3, 1), (1, 5), (5, 7)

a) f i n d t h e l i n e l_{1} j o i n i n g t h e p o i n t s

A a n d B

b) F i n d t h e l i n e l_{2} p e r p e n d i c u l a r

t o l_{1} a n d p a s s e s t h r o u g h t h e p o i n t

B

c) s h o w t h a t t h e p o i n t C l i e o n t h e

l i n e l_{2} h e n c e o r o t h e r w i s e f i n d

t h e a r e a o f t h e t r i a n g l e A B C .

Answered by ajfour last updated on 16/May/18

y - 1 = (\frac{1 - 5}{3 - 1}) (x - 3)

\Rightarrow y = 7 - 2 x

y - 5 = \frac{1}{2} (x - 1)

\Rightarrow 2 y = x + 9

2 y = 5 + 9 = 2 \times 7

△ = \frac{1}{2} ∣ | \begin{matrix} 3 & 1 & 1 \\ 1 & 5 & 1 \\ 5 & 7 & 1 \end{matrix} | ∣

= \frac{1}{2} ∣ - 6 + 4 - 18 ∣ = 10 s q . u n i t s .

Facebook Tweet Pin