If A+B=180 then prove that:
2(1-sinA. sinB)=cos²A+cos²B

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap

Find the equation of a line whose slope is 2/5 and y- intercept is 2.write your answer in the form 1) ax+by+c=02) x/a+y/b=1

The perimeter of an equilateral triangle is 4 cm more than the perimeter of a square and the length of a side of the triangle is 8 cm more than the length of a side of the aware. find the length of a side of the equilateral triangle