Respuesta :

Answer:

Step-by-step explanation:

24.57 cm

thebecks

Answer:

Choice 4) 78 cm^2

Step-by-step explanation:

OC = 7.8

AD = 10    (base = 10)

drop a line from the center where the 2 diagonals cross to be perpendicular to the base.

sin a2 = 1/2 height/7.8

1/2 height = 3.9

height = 7.8

area = 10 x 7.8 = 78 cm^2