The isoceles triangle is divided into 2 right-angled triangles so the length of one side can be calculated using trigonometric ratio
When the isoceles triangle is divided, the angle in the right-angled triangle is 20° (1/2 of 40°) and the base is 9cm (1/2 of 18 cm), the hypotenuse side is calculated using trigonometric ratio
Answer: Since you already know that the ordered pair is in the format of (x, y), then you can label one of the ordered pairs as 1 and kind of distribute it to get 1(x, y) = (x-sub1, y-sub1). Then just use the slope formula (y2-y1)/(x2-x1).
To find the mean/average, add up all the numbers and divide the sum by the # of numbers there are (ex. there are 11 numbers so divide the sum by 11).
The median is the middle number of a set. In this case, the middle number is easy to see because the # of numbers is odd, but if it was even, just find the average of the two middle numbers.
The mode is/are the most frequent number(s) in the set. In this set, the numbers that appear the most are 55 and 60.