8.GM.5a
Discover that the sum of the three angles in a triangle is 180 degrees.
Khan Academy ResourcesGetting ready for transformation propertiesTriangle angles reviewFinding angle measures between intersecting linesFinding angle measures using trianglesFind angles in trianglesAngle relationships with parallel linesEquation practice with anglesEquation practice with angle additionFind angles in isosceles trianglesAngles, parallel lines, & transversalsAngles in a triangle sum to 180° proofWorked example: Triangle angles (intersecting lines)Worked example: Triangle angles (diagram) Triangle exterior angle exampleIsosceles & equilateral triangles problemsEquation practice with supplementary anglesEquation practice with vertical anglesMeasures of angles formed by a transversalMissing angles with a transversal

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