I need help with this question!

Find and simplify an expression for the area of five rows of x squares with side lengths of x centimeters.

Average acceleration: i have no idea how to do this.

If two angles of a triangle have equal measures and the third angle measures 90°, what are the angle measures of the triangle? a. 60°, 60°, 60° b. 45°, 90°, 90° c. 30°, 30°, 90° d. 45°, 45°, 90°