Question

A hand fan is made by stitching 10 equal size triangular strips of two different types of paper as shown in figure. The dimensions of equal strips are 25 cm, 25 cm and 14 cm. Find the area of each type of paper needed to make the hand fan.

• A. 280 cm${}^2$
• B. 420 cm${}^2$
• C. 840 cm${}^2$
• D. 384 cm${}^2$

Answer 1

The correct option is C 840 cm${}^2$

The dimensions of equal strips are 25 cm, 25 cm and 14 cm.
Then area of each strip=$\sqrt{s(s-a)(s-b)(s-3)}=\sqrt{32(32-25)(32-25)(32-14)}=\sqrt{32\times 7\times 7\times 18}=168$
Then total the area of each type of paper needed=$168\times 5=840c{m}^2$