A triangle has coordinates A (1, 5), B (-2, 1) and C (0, -4) What are the new coordinates if the triangle is rotated 90° clockwise around the origin?
-
as long as it does not spin......
find slopes of lines from origin to the apices ... they are 5, -1/2 and infinity ...so afterr tilt the slopes are -1/5, 2 and 0.
lengths of these lines are sqrt26, sqrt5 and sqrt16 ... they will remain same( as rotated around origin) ... so, next co-rdinates will be ( 5, -1) (1,2) ( -4,0)... the sign allocation is as follows....
every apex goes only to next quadrant clockwise ...starting from C it goes from -ve yaxis to -ve x axix....A from QI to QIV and B from QII to QI .
find slopes of lines from origin to the apices ... they are 5, -1/2 and infinity ...so afterr tilt the slopes are -1/5, 2 and 0.
lengths of these lines are sqrt26, sqrt5 and sqrt16 ... they will remain same( as rotated around origin) ... so, next co-rdinates will be ( 5, -1) (1,2) ( -4,0)... the sign allocation is as follows....
every apex goes only to next quadrant clockwise ...starting from C it goes from -ve yaxis to -ve x axix....A from QI to QIV and B from QII to QI .