What degree of rotation will cause the triangle below to map onto itself ?

Answer:The triangle is rotated 360° ⇒ answer DStep-by-step explanation:* Lets revise some transformation- If point (x , y) rotated about the origin by angle 90° anti-clock wise∴ Its image is (-y , x)- If point (x , y) rotated about the origin by angle 90° clock wise∴ Its image is (y , -x)- If point (x , y) rotated about the origin by angle 180°∴ Its image is (-x , -y)* There is no difference between rotating 180° clockwise or   anti-clockwise around the origin- If point (x , y) rotated about the origin by angle 360°∴ Its image is (x , y)  the point itself* There is no difference between rotating 360° clockwise or   anti-clockwise around the origin* Now lets solve the problem∵ The vertices of the triangle ABC are:   A is (-6 , 3) , B is (-5 , 7) , C is (-4 , 3)∵ The triangle map onto itself∴ A = A'∴ B = B'∴ C = C'∴ The triangle is rotated 360° about the origin