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Julia made a model of a square pyramid. She used cardboard to construct the model with the dimensions shown. It has an open bottom.

A square pyramid has a square base with side lengths of 8 centimeters, and 4 triangular sides with a height of 5 centimeters.

What is the surface area of the model?
A. 80 cm2
B. 144 cm2
C. 224 cm2
D. 320 cm2

Respuesta :

semsee45

Answer:

A.  80 cm²

Step-by-step explanation:

If a square pyramid has an open base, then the surface area is made up of the 4 congruent triangular sides only.

Area of a triangle = 1/2 × base × height

Given:

  • Base = 8 cm
  • Height = 5 cm

⇒ Area of one triangular face = 1/2 × 8 × 5

                                                 = 20 cm²

⇒ Total surface area = 4 triangular faces

                                   = 4 × 20

                                   = 80 cm²

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