Answer:
135 units²
Step-by-step explanation:
The area (A) of a parallelogram is calculated as
A = bh ( b is the base and h the perpendicular height )
To calculate h use Pythagoras' identity on the right triangle on the left
h² + 8² = 17²
h² + 64 = 289 ( subtract 64 from both sides )
h² = 225 ( take the square root of both sides )
h = = 15 , thus
A = 9 × 15 = 135 units²