Area of triangle: 1/2(base)(height) Area of rectangle: length × width
Find the area of the triangles on the sides first using 1/2(base)(height). Plug 8 for the base and 6 for the height.
1/2(8)(6) = 24 units² Multiply 24 by 2 for both of the triangles. (24)(2) = 48 units²
Find the area of the rectangles of the object using length × width. For the rectangle on top, you can find the width using the Pythagorean Theorem: a² + b² = c².
Plug in 6 and 8 for a and b, and find c (width). 6² + 8² = c² 36 + 64 = 100 Square root both sides; √100 = 10. The width of the rectangle on top is 10.
Now plug 20 for the length and 10 for the width. 20 × 10 = 200 units²
For the rectangle on the bottom, plug in 20 for the length and 8 for the width. 20 × 8 = 160 units²
For the rectangle on the side, plug in 20 for the length and 6 for the width. 20 × 6 = 120 units²
Add up all the areas ⇒ 48 + 200 + 160 + 120 = 528 units².
