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.

Same length is comparing because it’s saying its the same and not different