My brother needs w numbers 3, 4, 7, 8, and 9! i haven’t taken geometry in years and he doesn’t have any notes on how to complete these problems he’s having trouble w.

3.) Since RECT is a rectangle, the corners must be 90 degrees each. Angle ECT is one of the corners, o we can set 11x+13 equal to 90.

11x + 13 = 90

11x = 77

x= 7

4.) The diagonals of a rhombus are perpendicular meaning they form 90 degree angles. So set 14x+6 equal to 90.

14x + 6 = 90

14x = 84

x = 6

7.) The diagonals of a square also form 90 degree angles. Since all the sides of a sqaure are equal, we know that SQR and QSR must be equal. Since QRS is 90 and the angles of a triangle must add to 180, we know that SQR is 45.

4x + 1 = 45

4x = 44

x = 11

8.) Set it equal to 90 like the first two problems.

11x + 2 = 90

11x = 88

x = 8

9.) It looks like he got 9 right! The two sides are equal lengths, so they can be set equal to each other to solve for x.