Question

A sign is being made from a rectangular board of wood that originally measures 36 inches by
18 inches. Triangles are to be cut from the board along the dotted lines so that the remaining
shape is an isosceles trapezoid whose shorter parallel side is 24 inches long as shown.

Answer 1

Solution (a):

• Area of rectangle = LB
• => Area of rectangle = 18 x 36
• => Area of rectangle = 648 in²

Solution (b):

Since the two triangles are equal (as said in the question):

• => Area of triangles: 2(1/2 x 6 x 18)
• => Area of triangles: 6 x 18
• => Area of triangles: 108 in²

Solution (c):

Subtract the area of the triangles from the area of the rectangle.

• 648 - 108 = Area of trapezoid
• => 540 in² = Area of trapezoid