Practice30Create account

Which term describes a polygon in which at least one interior angle is greater than 180°?

Class 8Understanding QuadrilateralsQuadrilaterals
  • AConcave polygon
  • BConvex polygon
  • CRegular polygon
  • DEquilateral polygon

Step-by-Step Solution

A polygon with at least one reflex (greater than 180°) interior angle, i.e. a 'dent', is concave. If all interior angles are less than 180°, it is convex.
Answer: A) Concave polygon

Key idea: Sum of interior angles

**Sum of interior angles of any quadrilateral = 360°.**

Why? Draw one diagonal — it splits the quadrilateral into two triangles. Each triangle has angles summing to 180°. Two triangles → 360°.

More generally: for an n-sided polygon, sum of interior angles = (n − 2) × 180°. For a quadrilateral, n = 4: (4 − 2) × 180° = 360°.

Master this chapter in 30 minutes a day.

Don't just memorise the answer — build a daily practice habit.

Practice 5 Similar Questions Free →

All Understanding Quadrilaterals practice questions

More Class 8 Understanding Quadrilaterals practice

The sum of the exterior angles of any convex polygon (one at each vertex) is always:In parallelogram ABCD, ∠A = 120°. Find ∠B in degrees.Which property is NOT necessarily true for every parallelogram?In parallelogram ABCD, side AB = 8 cm. What is the length of side CD?The diagonals of a parallelogram bisect each other. If one diagonal is 14 cm, each half…