Solve the following geometry problems involving angles and their definitions, including constructing a 90-degree angle.

Here are the solutions to the questions: 9. Answer the following question a) Define acute angle. An acute angle is an angle that measures greater than 0^ but less than 90^. b) Write the name of the angle formed in the straight line. The angle formed by a straight line is called a straight angle. It measures 180^. c) What is the straight line? A straight line is a one-dimensional figure that extends infinitely in both directions without any curve. It is the shortest distance between any two points on it. d) Find the value of x. Step 1: Identify the angles on the straight line AB. From the diagram, we have an angle of 120^ and an angle x on the straight line AB. Step 2: Recall that angles on a straight line sum to 180^. x + 120^ = 180^ Step 3: Solve for x. x = 180^ - 120^ x = 60^ The value of x is 60^. e) Construct the following angle by using compass and pencil. a) 90^ Step 1: Draw a line segment AB and mark a point O on it. Step 2: With O as the center, draw an arc of any convenient radius that intersects AB at two points, say P and Q. Step 3: With P and Q as centers, and a radius greater than OP, draw two arcs that intersect each other above (or below) AB at a point, say R. Step 4: Draw a line segment from O to R. The angle AOR (or BOR) is 90^. b) 30^ Step 1: Draw a line segment AB and mark a point O on it. Step 2: With O as the center, draw an arc of any convenient radius that intersects AB at a point, say P. Step 3: With P as the center and the same radius, draw another arc that intersects the first arc at a point, say Q. The angle QOP is 60^. Step 4: Now, bisect the 60^ angle. With P and Q as centers, and a radius greater than half the distance PQ, draw two arcs that intersect each other at a point, say R. Step 5: Draw a line segment from O to R. The angle ROP is 30^.