A grid is 10 squares high and 10 squares wide. The distance between each grid square is 3 feet. The triangular viewing area of c
amera is shown. The right triangle has 2 sides with lengths of 5 grid squares. The area of the triangle is 112.5 feet squared. Alan wants to install security cameras in his store, which has dimensions of 30 feet by 30 feet. Each camera can view an area of approximately 112.5 ft2, with a viewing area shaped like a right triangle.
How many cameras will be necessary to cover the entire store?
.
If he places cameras only in the corners of the store, how much area is left uncovered?
Each triangle takes half a square worth of space, so if you add up 2 triangles for 1 square that is 1/4 of the area, multiply that by 4 and you get 8 cameras.
The left over space in the store is the same amount of space as all the cameras space added together since each camera takes up half a square. That way 4 cameras(each 112.5 ft^2 each) equals 1/2 of the room which added together is 450 ft^2, the other half would be the left over space, 450 ft^2.