In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data:
radius = 10 m
Step 02:
area ( 90° sector) :
total area ( 360° ):
area = π r² = π (10 m)² = π * 100m² = 314.16 m²
area ( 90° sector):
360° / 4 = 90°
area = 314.16 m² / 4 = 78.54 m²
The answer is:
78.54 m²