tent
A complementary angle is two angles whose sum is 900 (degrees). So you would need a triangular shaped structure whose bottom angles are 450 each. Possibly an Egyptian pyramid?
A basic camping tent, a house roof, and the iconic Toblerone box.
a pencil
The Equator is a real world example, being the circumference of the Earth.
The 4500 year old Great Pyramid of Giza, Egypt. This real life example is also the last remaining of the "Seven Wonders of the World" in existence.
Roof tops
an Egyptian pyramid
A square pyramid is a polygon that has a square base and four triangular sides. A real life example is the Great Pyramid of Giza in Egypt.
roof
pizza, pyramid, mountains, beak of particular birds, etc
Roof of a house
A pyramid like in Egypt or something like that. Or a triangular tent
tent
it is michal Jackson
One real world example of a square pyramids is the pyramids built in Egypt, like the Pyramid of Giza. Another example is the roof of many houses. Children's building blocks often include square pyramids as well.
One of the examples of a real-life pyramid is the Great Pyramid of Giza.