The remaining area that the grass will cover will be given by: Area=[area of rectangle]-[area of the triangle] area of rectangle will be: A1=length*width =20*8 =160 square feet The area of the triangle will be: A2=1/2absin theta since the triangle is equilateral, all the angles are equal and the size of each angle is 60°. Thus the area will be: A2=1/2*5*5sin 60 =18.3 thus the remaining area of the grass will be: Area=160-18.3 =149.7 square feet
Pythagoras is planting a rose garden in the center of his rectangular yard, which is 20 feet long and 8 feet wide. He wants to dig up an area in the shape of an equilateral triangle with sides 5 feet each. After he digs up the rose-bed section, approximately how much grass will be left? Round to the nearest foot.