Use the image to answer the question.

A composite shape is drawn using a rectangle and 2 triangles. A horizontally aligned rectangle is 9 centimeters long and 3 centimeters wide. A right triangle facing upward adjoins the rectangle on the left side marked 3 centimeters. A right triangle facing downward adjoins the rectangle on the right side. The base leg of both triangles measures 2 centimeters.

Hector designs the piece of jewelry shown below. All lengths are marked in centimeters. What is the total area of the piece of jewelry?

(1 point)
Responses

39 square centimeters
39 square centimeters

30 square centimeters
30 square centimeters

27 square centimeters
27 square centimeters

33 square centimeters

1 answer

To find the total area of the composite shape, we can break it down into its components: the rectangle and the two triangles.

  1. Area of the rectangle: The area of a rectangle is given by the formula: \[ \text{Area} = \text{length} \times \text{width} \] Here, the length is 9 centimeters and the width is 3 centimeters. \[ \text{Area of the rectangle} = 9 , \text{cm} \times 3 , \text{cm} = 27 , \text{cm}^2 \]

  2. Area of each triangle: The area of a right triangle is given by the formula: \[ \text{Area} = \frac{1}{2} \times \text{base} \times \text{height} \] Each triangle has a base of 2 centimeters and a height of 3 centimeters.

    For one triangle: \[ \text{Area of one triangle} = \frac{1}{2} \times 2 , \text{cm} \times 3 , \text{cm} = \frac{1}{2} \times 6 , \text{cm}^2 = 3 , \text{cm}^2 \]

    Since there are two triangles: \[ \text{Total area of the triangles} = 2 \times 3 , \text{cm}^2 = 6 , \text{cm}^2 \]

  3. Total area of the jewelry piece: Now we add the area of the rectangle and the areas of the triangles: \[ \text{Total area} = \text{Area of rectangle} + \text{Total area of triangles} \] \[ \text{Total area} = 27 , \text{cm}^2 + 6 , \text{cm}^2 = 33 , \text{cm}^2 \]

Thus, the total area of the piece of jewelry is 33 square centimeters.