The circle is inscribed in the quadrilateral ABCD. Find P of a quadrilateral if AB + CD = 5 cm

Given:
quadrangle ABCD,
a circle is inscribed in a quadrilateral ABCD,
AB + CD = 5 centimeters.
Find the perimeter of the quadrilateral ABCD, that is, P ABCD -?
Solution:
Consider the quadrilateral ABCD. We know that a quadrilateral can be described around a circle if the sum of the lengths of its opposite sides is equal, that is, the equality must be true:
AB + CD = BC + AD.
Since AB + CD = 5 centimeters and P ABCD = AB + CD + BC + AD;
P ABCD = 5 + 5;
P ABCD = 10 centimeters.
Answer: 10 centimeters.