Answer :
The value of the height of the prism is 8.68 inches
Surface of a square pyramid
The surface area is the sum of the area of the faces.
The formula for calculating the surface area of the pyramid is;
TSA = [tex]a^2+2a\sqrt{\frac{a^2}{4} + h^2}[/tex]
where
a is the side length. = 7in
h is the height
Substitute
[tex]189=7^2+2(7)\sqrt{\frac{7^2}{2} + h^2} \\189=49+14\sqrt{\frac{49}{2} + h^2}\\140=14\sqrt{\frac{49}{2} + h^2}\\10=\sqrt{\frac{49}{2} + h^2}\\[/tex]
Square both sides to have
100 = 49/2 + h²
h² = 100 - 49/2
h² = 151/2
h² = 75.5
h = 8.68in
Hence the value of the height of the prism is 8.68 inches
Learn more on surface area here; https://brainly.com/question/1297098
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