Answer: A = 61.8 square units
Explanation:
Hi, we have to apply the Trigonometric area formula:
A = 1/2 ab sin (c)
Where a and b are the sides ( in this case we use the sides that are given to us, which are 10 and 13 ) and c is the included angle.
So, replacing the formula with the given values:
A = 1/2 (10) (13) sin 72°
A = 61.8 square units
Feel free to ask for more if it´s necessary or if you did not understand something.