Answer:
1,620 square inches
Step-by-step explanation:
The area of one triangle can be computed using the formula ...
A = 1/2bh . . . . where b represents the base length, h represents height
A = 1/2(18 in)(36 in) = 324 in²
Then the area of 5 flags will be 5 times that much:
fabric needed = 5 × (324 in²) = 1,620 in²
Brian will need 1,620 square inches of fabric for his 5 triangular flags.
