Jawaban:

The area of the remaining piece of paper is 1350 cm².

Penjelasan:

The area of the remaining piece of paper can be found by substracting the area of the rectangular construction paper by the total area of the cut.

Sharon cut away 5 triangles there, so the total area of the cut is 5 times the area of each triangle. The base of each triangle is:

60/5 = 12 cm

while its height is 15 cm.

Put those information into a formula:

A = A▭ – 5×A▽

A = (60×30 – 5×(1/2)×12×15) cm²

  = (1800 – 450) cm²

  = 1350 cm²

∴ Therefore, the area of the remaining piece of paper is 1350 cm².