Question

The sum of all angles in a quadrilateral is equal to _________ right angles.
A. 2
B. 3
C. 4
D. 360

Answer 1

Hint: We will be using the properties of quadrilaterals, especially the angle sum property. The sum of the angles of an n-sided polygon is given by $(n - 2)180^{\circ} $.

Complete step-by-step solution -
We know that a quadrilateral is a polygon of 4 sides. It may or may not be regular. A right angle is the one whose value is $90^{\circ}$. Hence, we will find the sum of all angles and then divide it by 90 to find the number of right angles in a quadrilateral.

The sum of angles of a quadrilateral = $(n - 2)180^{\circ} $ = $(4 - 2)180^{\circ} $ = $360^{\circ}$
The number of right angles in $360^o$ are
$$=\dfrac{360}{90}=4$$
This is the required answer. The correct option is C. 4.

Note: We can use the formula for angle sum for any number of polynomials, irrespective of the number of sides or it is regular or not. One should also remember that a right angle represents $90^o$, as it is used very commonly.