1. A square of side 5 cm and 4 isosceles triangles of base 5 cm and height 8 cm are to be put together to make a square pyramid how many square centimetres of paper is needed?
Answers
We need to find the area of the paper used.
Total triangles required for sq. pyramid = 4
Total amount of paper used for sq. pyramid = (Area of sq) + (4 × Area of isosceles triangles) ----- ( i )
Step-by-step explanation:
Area of sq. = s×s
= 5 cm × 5 cm
= 25 cm²
Area of triangle = ½•b•h
= ½ • 5 cm • 8 cm
= 20 cm²
Plugging in the values in ( i ), we get,
(25 cm²) + (4 × 20 cm²)
= 25 cm² + 80 cm²
= 105 cm²
Answer:
105 sq. cm
Step-by-step explanation:
Area of the paper is equal to the surface area of the square pyramid.
Area of the square = 5*5 = 25 sq. cm.
Base of the triangles = 5 cm
height = 8 cm
Area of each triangle = 1/2*5*8 = 20 sq.cm
Then, surface area of the pyramid = 25+4*20
= 105 sq.cm
Area of the paper needed = 105 sq. cm