diagonals of an isosceles trapezoid are perpendicular to each other and the sum of the lengths of its bases is 2a. what is its area? !

Question and answers are in the attached picture. you so much in advance.

The perimeter of a rectangle is 42 inches. if the width of the rectangle is 6 inches, what is the length

Solve these problems: 1.what is the perimeter of an equilateral triangle with sides measuring 6cm? 2. a regular pentagon has sides measuring 3.2 cm. what is its perimeter? 3. a regular decagon has sides of 3.5mm . what is it’s perimeter? 4. a regular octagon has a perimeter of 64cm. what is the length of one of the sides? 5. a regular hexagon has a perimeter of 72mm . what is the length of one of the sides? 6. what is the perimeter of a rhombus with sides measuring 11m?