The area of the right angle isosceles triangle in the following two circles is 5 square centimeter

The area of the right angle isosceles triangle in the following two circles is 5 square centimeter

(1) 12r2 = 5, so R2 = 10, 3.14 × 10 = 31.4 (square centimeter), a: the area of this circle is 31.4 square centimeter. (2) 2R × R △ 2 = 5, so R2 = 5, 3.14 × 5 = 15.7 (square centimeter), a: the area of this circle is 15.7 square centimeter