Can anyone me with this! angle adfition postulate

Points d and e are midpoints of the sides of triangle abc. the perimeter of the triangle is 48 units. what is the value of t? ο ο ο ο 7t +

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

Apark is in the shape of a rectangle. the park authorities are planning to build a 2-meter-wide jogging path in the park (shown as the shaded region in the image). what is the area of the jogging path? plz