A composite shape is drawn using a rectangle and a triangle. The rectangle has a base labeled as 6 centimeters. A triangle showing a perpendicular height of 6 centimeters is stacked on the top side of the rectangle. The base of the triangle and the top of the rectangle have a common side. Right angle symbols are shown on all four corners of the rectangle.

The area of the drawing is 78 square centimeters. What is the height of the rectangle?

1 answer

Let the height of the rectangle be h centimeters.

The area of the rectangle is given by: 6h

The area of the triangle is given by: 1/2 * base * height = 1/2 * 6 * 6 = 18

Therefore, the total area of the composite shape is: 6h + 18 = 78

6h + 18 = 78
6h = 60
h = 10

Therefore, the height of the rectangle is 10 centimeters.