Dedrea is making a bike ramp on the sidewalk in front of their house. They place a wood plank on top of blocks to form the ramp. The blocks are one foot in height, and the distance from the base of the blocks to where the wood plank touches the sidewalk is five feet. What is the approximate angle formed between the sidewalk and the base of the ramp?

23°
23°

79°
79°

45°
45°

11°

To find the angle, we can use the tangent of the angle, which is equal to the opposite side (the height of the blocks) divided by the adjacent side (the distance from the base of the blocks to where the wood plank touches the sidewalk).

tan(angle) = opposite / adjacent
tan(angle) = 1 foot / 5 feet

Now, we can use the inverse tangent function to find the angle:

angle ≈ arctan(1/5) ≈ 11.31°

Therefore, the approximate angle formed between the sidewalk and the base of the ramp is 11°.