Cho tam giác ABC. Gọi M, N lần lượt là trung điểm AB, AC, trên tia đối tia NM lấy điểm D sao cho N là trung điểm MD, cm: a, CD song song AM

b, CD = MB

c, tam giác BMC = tg DCM

d, MN ss BC

e, MN = 1/2 DC

He expression 2(l + w) is used to calculate the perimeter of a rectangle, where l is length and w is width. if the length is fraction 2 over 3 unit and the width is fraction 1 over 3 unit, what is the perimeter of the rectangle in units? fraction 2 over 3 unit 1 unit 1fraction 2 over 3 units 2 units

Look at arnold's attempt to solve the equation for b: 3b = 12 b = 3 · 12 b = 36 describe the mistake that arnold made.

The length of a rectangle plus its width is 25 cm. the area is 156 square cm. what are the length and width of the rectangle? separate the answers with a comma.