Name: christina

Who is asking: Student
Level: Secondary

Question:
hey, i have a question about a problem on my homework. i did the problem, but i'm not sure if the answer is right so i want to check with you. so if you could help me i would really appreciate it. the problem reads:

The Great Pyramid is the largest of the Egyptian pryamids. When it was built, it was 481 feet tall and had a square base with 755-foot sides. The pyramid has two different slopes-one along its sides and the other along its edges. Which slope is steeper? (hint: you need the pythagorean theorem to find the slope along the pyramid's edges.)

when i did the problem, i got the slope of the sides to be 481/533.9 (9) and the slope of the edges to be 481/377.5 (1.27). therefore, the slope of the sides of the pryamids is steeper. and so if that is right could you please email me and tell me. also, the 2nd part of the question is to explain, and i don't know how to explain why that is so. if you could help me, i would greatly appreciate it. thanks, Christina



Hi Christina,

I got the same slopes as you, but you don't need to do the arithmetic to see which is larger. In the diagram below the slope along the side is the slope of SP and the slope along the edge is the slope of CP.

The slope of SP is  |PB|/|BS| and the slope of CP is  |PB|/|BC|. The numerators of these fractions are the same and from the diagram |BC| > |BS|. Hence the slope of SP is larger than the slope of CP.

Cheers,
Penny

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