Test: Quadrilaterals - 1 - Class 8 MCQ

Correct Answer :- b

Explanation:- A rhombus is a  parallelogram and a quadrilateral whose opposite sides are parallel and opposite angles are equal.

Area of Rhombus, A = (d1 x d2)/2

The perimeter of Rhombus, P = 4a units

The opposite angles of a rhombus are equal to each other.

In a rhombus, diagonals bisecting each other at right angles.

Diagonals bisect the angles of a rhombus

- When the sides of a triangle are extended, each exterior angle formed is the supplementary angle to the interior angle.
- The sum of the exterior angles of any polygon, including triangles, is always 360°.
- This is because each exterior angle is effectively a turn around the triangle, adding up to a full circle.
- Thus, regardless of the triangle's type, the sum of the exterior angles formed is 360°.
- Therefore, the correct answer is D: 360°.

BC ( because of opposite sides of the parallelogram are equal = )

In any triangle, the sum of the measures of the three interior angles is always 180 degrees. This fundamental property, known as the angle sum property of triangles, holds true for all types of triangles:

• Acute triangles
• Obtuse triangles
• Right-angled triangles

This property is derived from Euclidean geometry. When you draw a triangle, if you extend one of its sides and construct a line parallel to the other side, the angles will form supplementary pairs. This results in the total sum of 180 degrees.

In a rhombus, the diagonals are perpendicular bisectors of one another. This means that:

• The diagonals intersect at right angles (90 degrees).
• Each diagonal divides the other into two equal parts.

Thus, the correct answer is Option C: diagonals.

We are given a parallelogram with one angle marked as 50°, and we are to find the value of x (an interior angle).

Opposite angles are equal.

The angle labeled 50° and angle x are adjacent angles of the parallelogram.

Adjacent angles are supplementary (i.e., they add up to 180°).

Correct option is A.

It’s a property of parallelogram that opposite sides of a parallelogram are equal and parallel.

If two adjacent sides of a parallelogram are equal, then it is a rhombus.. A quadrilateral whose diagonals bisect each other at right angles is a rhombus.

In square all sides are equal and every angle is right angle.

Kite, is a quadrilaterals has two pairs of adjacent sides equal and diagonals intersecting at right angles. 

A regular polygon with five sides is known as a pentagon.

Key points about pentagons:

• A pentagon has exactly five sides.
• Each internal angle in a regular pentagon measures 108 degrees.
• The sum of all interior angles in a pentagon is 540 degrees.