#3**+2 **

Here is an image to maybe help see this:

sum of green angles = 4 * 180° | because the sum of interior angles in each triangle is 180° | |

sum of pink angles = 360° | because the sum of interior angles in a quadrilateral is 360° | |

(see this by drawing two triangles inside a quadrilateral.) | ||

sum of purple angles = sum of pink angles | because vertical angles are congruent. | |

sum of orange angles = sum of green angles - sum of purple angles

sum of orange angles = 4 * 180° - 360°

sum of orange angles = 360°

(I apologize if you are colorblind!!)

hectictarNov 16, 2019