Question

Shape	Centre of rotation	Order of rotation	angle of rotation
Equilateral Triangle	P
Rectangle		Q
Square	R		S

Find P, Q, R and S respectively.

• A. Intersection point of medians, 2, intersection point of diagonals, ${90}^o$
• B. Intersection point of medians, 2, intersection point of diagonals, ${180}^o$
• C. Intersection point of altitudes, 4, intersection point of diagonals, ${25}^o$
• D. Intersection point of sides, 4, intersection point of diagonals, ${45}^o$

Answer 1

The correct option is A Intersection point of medians, 2, intersection point of diagonals, ${90}^o$

In equilateral triangle the center lies at point of intersection of medians. which gives the centre of rotation.

So, $P$ $=$ intersection point of medians.

A rectangle has order of rotation $2$ because at ${180}^o$ it will look same

After rotating ${360}^o$, it will again look same

So, $Q=2$

In square, the centre of rotation is given by intersection point of diagonal because diagonal of square bisects each other at ${90}^o$ degree.

So, $R=$ intersection of point of diagonal

As all side of square are equal, so after rotating by ${90}^o$ it will look same

So, $S={90}^o$