Question

The four folded parts of an envelope are opened up to create this figure. What is the surface area of one side of the unfolded envelope?

A. 25 square centimeters
B. 37 square centimeters
C. 50 square centimeters
D. 64 square centimeters

Answer 1

C

Explanation:

The total area comprises of the rectangle (area is base * height) and the 4 triangles (area = 1/2 * base * height).

Area of rectangle = 6 * 4 = 24

Area of top triangle = 1/2 * 6 * 3 = 9

Area of bottom triangle = 1/2 * 6 * 3 = 9

Area of rightside triangle = 1/2 * 4 * 2 = 4

Area of leftside triangle = 1/2 * 4 * 2 = 4

Let's add them up and find the correct answer:

Area = 24 + 9 + 9 + 4 + 4 = 50

Answer 2

Option C. 50 square centimeters

Explanation:

we know that

The surface area is equal to the area of four triangles plus the area of rectangle

so

`SA=2[(1)/(2)(4)(2)]+2[(1)/(2)(6)(3)]+(6)(4)`

`SA=8+18+24`

`SA=50\ cm^(2)`