Ages 11–14🧮 Mathematics28 verified questions on this shelf

Angle sums in triangles and polygons

Derive and use the angle sum in a triangle (180°), use it to deduce the angle sum in any polygon ((n−2) × 180°), and calculate interior and exterior angles of regular polygons

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Question 1 of 3

A triangular banner has two interior angles that measure 45° and 70°. What is the size of the third interior angle?

Question 2 of 3

In triangle ABC, AB = 7 cm and AC = 9 cm. The internal bisector of angle A meets side BC at point D, and BD = 4 cm. What is the length of CD?

Question 3 of 3

What is the distance between the points (2, -1) and (5, 3) on the coordinate plane?

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Skill names and descriptions include the Marble Skill Taxonomy © Generative Spark, Inc. (withmarble.com), licensed under ODbL 1.0 (database) and CC BY-SA 4.0 (content). Practice questions are GlowGrades's own, each checked by independent verifiers that must agree before a child ever sees it.