- A110
- B120
- C240
- D130
Step-by-Step Solution
∠B and ∠D are opposite angles of the parallelogram, so they are equal. ∠D = 120°.
Answer: B) 120
In a parallelogram ABCD, ∠B = 120°. What is the measure of ∠D (in degrees)?
Class 9QuadrilateralsGeometry — Quadrilaterals
Key idea: Special parallelograms
**Rectangle** (parallelogram + all angles 90°):
- All properties of a parallelogram.
- Diagonals are EQUAL (in addition to bisecting each other).
**Rhombus** (parallelogram + all sides equal):
- All properties of a parallelogram.
- Diagonals bisect each other AT RIGHT ANGLES.
- Diagonals also bisect the angles of the rhombus.
**Square** (rectangle + rhombus):
- All properties of both.
- Diagonals: equal, bisect at right angles, AND bisect angles.
- All properties of a parallelogram.
- Diagonals are EQUAL (in addition to bisecting each other).
**Rhombus** (parallelogram + all sides equal):
- All properties of a parallelogram.
- Diagonals bisect each other AT RIGHT ANGLES.
- Diagonals also bisect the angles of the rhombus.
**Square** (rectangle + rhombus):
- All properties of both.
- Diagonals: equal, bisect at right angles, AND bisect angles.
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