Lines & Angles
This angle measures exactly 90°. What is it called?
A Right Angle
Sketch a polygon with 3 sides and 1 right angle. Label the right angle.
What is the most accurate name for this shape?
A RIGHT triangle
What kind of lines never meet, no matter how far they are extended?
Parallel Lines
A square has how many lines of symmetry?
(prove with a drawing)
4
You have a square that has a side length of 7 inches.
What is the area?
What is the perimeter?
Area = 49 square inches
Perimeter = 28 inches
Use your protractor to measure the given angle
(see problem #2 on the pre-assessment)
45 degrees
True or False: A right triangle can belong in a group of “shapes with at least one obtuse angle.”
False (a triangle can’t have both a right and obtuse angle).
Draw two line segments that are parallel on your geoboard.
see sketch
A rectangle has how many lines of symmetry?
(prove with a drawing)
2
Find the area of a rectangle: length = 25 in., width = 15 in.
25 × 15 = 375 in².
Sketch an angle that measures 30°
see sketch
(example: draws a 90 degree angle and then cuts it into three equal parts, then shades one of those areas darker)
Sketch a quadrilateral that is NOT a parallelogram.
Draws a Trapezoid OR a Kite
Draw two line segments that are perpendicular to each other.
see sketch
Sketch a polygon with exactly 1 line of symmetry. Label the line.
Isosceles Triangle
Find the perimeter of a rectangle: length = 144 cm, width = 36 cm.
2 x (144 + 36) 360 cm.
or
144 + 36 + 144 + 36 = 360cm
Sara divided a right angle into two angles:
b = 25°
c = ?
What is angle c?
65 degrees
(25 + 65 = 90 degrees)
A triangle has side lengths of 6 cm, 6 cm, and 10 cm. What type of triangle is it, and does it have any lines of symmetry?
It is an isosceles triangle, and it has 1 line of symmetry down the middle.
Which are the 4 types of quadrilateral that always have two pairs of parallel sides?
Parallelogram
Rectangle
Rhombus
Square
Sketch a quadrilateral with exactly 2 lines of symmetry. Label them.
Rectangle (not a Square)
If a square’s perimeter is 64 units,
what is the length of one side
What is its area?
Side = 16 units
Area = 256 units².
A polygon has 2 acute angles and 2 obtuse angles. Sketch and label the acute and obtuse angles.
See Sketch
A quadrilateral such as a kite or irregular quadrilateral with correct labels.
A polygon with 4 sides and one set of parallel sides is called what?
Trapezoid
Why can’t a right triangle belong in the “two pairs of parallel sides” group?
Because triangles only have 3 sides, so they can’t have pairs of parallel sides.
Which has more lines of symmetry—a square or an equilateral triangle?
Square (4) vs. Equilateral Triangle (3)
A rectangle has a perimeter of 48 cm.
If the length is 14 cm, what is the width?
What is the area?
14 + 14 + 2 x _____ = 48
Area = 14 × 10 = 140 cm².