Question

In the following figure,
find the measure of x.
A
B
40°
Х
>D
С​

Answer 1

Answer:

60

Step-by-step explanation:

606060606060606060606060606060y06060y0y0y

Answer 2

Answer: What is the sum of the measures of the angles of a convex quadrilateral? Why this property hold if the quadrilateral is not convex? (Make a non-convex quadrilateral and try!)

Ans. Angle sum of a convex quadrilateral = (4 – 2) × 180° = 2 × 180° = 360°           Since, quadrilateral, which is not convex, i.e. concave has same number of sides i.e. 4 as a convex quadrilateral have, thus, a quadrilateral which is not convex also hold this property. i.e. angle sum of a concave quadrilateral is also equal to 360°