triangle

• Jun 6th 2007, 04:38 AM
Alexander
triangle
triangle PQR is a right triangle in the Cartesain plane with right angle at R.P = (-2,1), Q = (4,3) and R lies vertically above P. the midpoint of PQ is M.

WHITCH ONE OF THE FOLLOWING IS/ARE TRUE?

A. R=(-2,3)

B. M=(1,2)

C. D (R,M) = (( sqeare root of 5 ) units)
• Jun 6th 2007, 05:18 AM
(-2,1), (4,3)
it should be letter B
since
the formula of midpoint is

$\displaystyle x_{mid}=\frac{x_1+x_2}{2}$
so
$\displaystyle x_{mid}=\frac{-2+4}{2}$

$\displaystyle x_{mid} = 1$

$\displaystyle y_{mid}=\frac{y_1+y_2}{2}$
so
$\displaystyle y_{mid}=\frac{3+1}{2}$

$\displaystyle y_{mid} = 2$

the answer is M = (1,2)
• Jun 6th 2007, 05:43 AM
CaptainBlack
Quote:

Originally Posted by Alexander
triangle PQR is a right triangle in the Cartesain plane with right angle at R.P = (-2,1), Q = (4,3) and R lies vertically above P. the midpoint of PQ is M.

WHITCH ONE OF THE FOLLOWING IS/ARE TRUE?

A. R=(-2,3)

B. M=(1,2)

C. D (R,M) = (( sqeare root of 5 ) units)

R is verticaly above P so their x co-ord are the same, and as the angle at R
is right the y co-ord of R is the same as Q, so R is (-2,3)

The mid point of PQ is ((-2+4)/2, (1+3)/2)=(1,2)

The distance from R to M is sqrt((-2-1)^2+(3-2)^2) = sqrt(10).

RonL