Line, Line Segment and Ray
Extends forever in both directions.
Line
What type of angle measures 90°?
Right angle.
How many sides does a triangle have?
3 sides
How many right angles does a rectangle have?
4 Right Angles
The angles in a triangle are 50°, 60°, and x. Find x
50 + 60 + x = 180
110 + x = 180
x = 70 o
Meets or cross at a point.
Intersecting Line
What type of angle measures 45°?
Acute Angle
Which shape has no sides and no corners?
A circle
Which has more sides: octagon or pentagon?
Pentagon
A square garden has a side length of 15 m. What is the perimeter of the garden?
Perimeter = 4 × 15
= 60 m
A part of a line with one endpoint that extends infinitely in the other direction.
Ray
What do we call an angle that measures more than 180° but less than 360°?
Reflex angle
Which shape has two pairs of parallel sides: a rectangle or a triangle?
Rectangle
What do we call shapes with many sides such as pentagons, hexagons, and octagons?
Polygons
A triangle has a perimeter of 20 cm. Two sides are 6 cm and 7 cm. What is the third side?
Answer:
6 + 7 = 13
20 − 13 = 7 cm
Meet or cross each other to make a square corner
Perpendicular Lines
When the hands of a clock show 3:00, what type of angle is formed?
Right Angle
A square has sides of 50 cm each. What is its perimeter?
50+ 50 + 50 + 50 = 200 cm
A stop sign is shaped like which 2D figure?
Octagon
A rectangle has a perimeter of 30 cm. The length is 10 cm. Find the width.
Perimeter = 2(L + W)
30 = 2(10 + W)
15 = 10 + W
W = 5 cm
Same distance apart and do not ever intersect.
Parallel Lines
Angles on a straight line add up to 180°. If one angle is 60°, what is the other angle?
120o
A rectangle has length = 28 cm and width = 32 cm. What is the area?
Area = 28 × 32 = 896 cm²
A square has a perimeter of 20 cm. What is the length of one side?
20 ÷ 4 = 5 cm
The area of a square is 36 cm². What is its perimeter?
24cm2