Standards with the same topic and subject but for other gradesA vertex is the point at which two or more lines, line segments, or rays meet to form an angle. The term vertices is the plural form of vertex. A right angle measures exactly 90 degrees. The student will measure right, acute, obtuse, and straight angles. An angle is formed by two rays with a common endpoint called the vertex. Angles are found wherever lines and/or line segments intersect. Intersecting lines have one point in common. Solve addition and subtraction problems to find unknown angle measures on a diagram in practical and mathematical problems, (e.g., by using an equation with a symbol for the unknown angle measure). An angle is formed by two rays that share a common endpoint called the vertex. Angles are found wherever lines or line segments intersect. Recognize angle measure as additive. When an angle is decomposed into nonoverlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Measure right, acute, straight, and obtuse angles, using appropriate tools, and identify their measures in degrees. A vertex is a point at which two or more lines, line segments, or rays meet to form an angle. In solid figures a vertex is the point at which three or more edges meet.