Question

apply a blender has blades as shown. what rotation will map
the blade formed by △abc onto the blade formed by △def?

Explanation:

Step1: Identify center of rotation

The blender blades are symmetric around the central point (shared vertex of all triangles).

Step2: Determine rotation direction

The blade △DEF is positioned clockwise from △ABC.

Step3: Estimate rotation angle

The blender has 4 blades, so each blade is separated by $\frac{360^\circ}{4} = 90^\circ$.

Answer:

A 90-degree clockwise rotation about the center of the blender blades.