Question

Find co-ordinates of the point $A(4,7)$ obtained by rotating it through ${180}^o$ about origin.

• A. $A^{\prime }(4,7)$
• B. $A^{\prime }(-4,-7)$
• C. $A^{\prime }(-4,7)$
• D. $A^{\prime }(4,-7)$

Answer 1

The correct option is B $A^{\prime }(-4,-7)$

Given co-ordinate of the point $A(4,7)$ which lies on first quadrant

Now either rotate it through ${180}^o$ about origin or rotate the co-ordinate axis through ${180}^o$

It will move from $1^{st}$ quadrant to $3^{rd}$ quadrant , hence now it will situated at $(-4,-7)$ i.e. on ($3^{rd}$ quadrant )