Areas
What is the Formula for area of a rectangle?
Length x width
7/10 or 3/5
7/10
A triangle has sides 3 cm, 5 cm, and 6 cm.
It is dilated by a scale factor of 2.
What are the side lengths of the new triangle?
6 cm, 10 cm, 12 cm
The sum of the angles in any triangle is always:
180 degrees
What is the formula for the area of a triangle?
1/2 (base x height)
4/9 or 1/2
1/2
When a figure is dilated, which of the following stays the same?
A. Side lengths
B. Angles
C. Perimeter
D. Area
B. Angles
A triangle has angles measuring 45° and 65°.
What is the measure of the third angle?
70
length x height
0.3 or 3/8
3/8
A point at (–2, 4) is dilated by a scale factor of 3 from the origin.
What are the coordinates of the image?
(–6, 12)
A triangle has angles measuring 50°, 60°, and 70°.
What type of triangle is it?
Acute
what does area represent?
the interior space of a shape
2/3 of 60 or 3/4 of 50
2/3 of 60
A shape is dilated by a factor of 2 from the point (2, 2) instead of the origin.
How would the new image be different from one dilated from the origin?
It would be the same size and shape, but located in a different position—shifted so that it stays “anchored” to (2, 2) as the center.
A triangle has side lengths 5 cm, 5 cm, and 8 cm.
What type of triangle is it?
Isosceles
What is missing from this statement:
The area of my bedroom is 70 ft
Units of area are squared because they represent 2d space not lines.
(5/6)2 or 3/4
3/4
A triangle has an area of 15 cm².
It is dilated by a scale factor of 4.
What is the area of the new triangle?
15×42=15×16=240 cm2
In a triangle, one angle is twice as large as another, and the third angle is 60°.
Find the measures of all three angles.
Let the smallest angle be x, the next is 2x, and the third is 60°.
x + 2x + 60 = 180 → 3x = 120 → x = 40°
Angles = 40°, 80°, and 60°