Answer:
92.75 cm²
Explanation:
area of polygon = area of ∆EDA + area of ∆ADC +area of ∆ACB.
area of triangles is ½×base×height.
area of ∆EDA=½×EF×AD
=½×4.5×12
=27 cm². -------->(1)
area of ∆ADC=½×AD×DC
=½×12×5
=30 cm². --------->(2)
area of ∆ACB=½×AC×BG
=½×AC×5.5
from pythagorean theorem
(AC)²=(AD)²+(CD)²
= 25+144
= 169 cm then. AC= 13 cm
then area of ∆ACB=½×5.5×13
=35.75 cm² ---------->(3)
from equation (1), (2) and (3):
then the area of polygon = 27 + 30 + 35.75
=92.75 cm²