Pyramids and cones (finding surface area). !

For the first one

notice, the pyramid is just 4 triangles and one square, stacked up to each other at the edges

now, for the first one, you have a square 4x4 and four triangles or base 4 and height of 6

bear in mind, the pyramids are called "regular pyramids" because their base is a regular polygon, meaning, a polygon with all equal sides, in this case a quadrilteral, or a square

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now for the second one

you have the height of the pyramid, but not the slant-height, which will be the height of the triangular face

thus... check the picture below, using the pythagorean theorem, you can just get the height of the triangular face then

now, the base of the triangles are all 22
and the base of the pyramid is a 22x22 square

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now, for the third one

same as the first one really, you have both, the base and slant-height, which will be the height of the triangular face

so, four triangles with a base of 6 and a height of 9, and a square on the base of 6x6

so... get the area of all four triangles, and the squarish base, sum them up, and that's the surface area of the pyramid

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