The formula you use to find the circumference of a circle is πR² or pi x radius x radius, so since your radius is 14, the answer would be A.
Answer:
(a) AD=6 cm
(b) 66 cm²
(c) 38 cm
Step-by-step explanation:
(a) To get the length of AD, we can use pythagoras on the triangle part. Let's say the dotted line intersects DC at E. Then since AB and DC are parallel, AD is equal to BE. EC = 8 cm simply by subtracting AB from DC (15-7=8).
Then pythagoras says that 8²+BC²=10². So BC = √(100-64) = 6. And since BC=AD, AD is also 6.
(b) Area of the rectangle DEBA is 7*6 = 42. Area of triangle ECB is base times half height: 8*3 = 24. Sum is 42+24 = 66 cm²
(c) Perimeter is 7+10+15+6 = 38 cm. Add all the side lengths.
[[x]] means that the integer should be rounded down to the greatest integer that is of the same value as x or is lower than x.
In standard form the equation is 3x + -4y = -12
