Answer:
1. D
2. B
3. A
4. C
Step-by-step explanation:
1. Vertical angles are a pair of opposite angles formed by the intersection of lines. Choice D has two lines intersecting, and two opposite angles formed by it.
2. Adjacent angles are two angles that have a common vertex and common side but do not overlap. Choice B is two angles with a common vertex and common side, and they don't overlap.
3. Supplementary angles are angles that add up to 180 degrees/make a straight angle. Choice A has two angles that add up to 180 degrees, and the two angles combined make a straight angle/line.
4. Two angles are called complementary angles if they add up to 90 degrees and form a right angle. Choice C has two angles that form a right triangle, meaning it adds up to 90 degrees.
9514 1404 393
Answer:
x = 12.75
∠C = 51.75°
Step-by-step explanation:
The two marked angles are complementary, so ...
(5x -12) +(3x) = 90
8x = 102
x = 102/8
x = 12.75
__
C = (5x -12)° = (5(12.75) -12)°
∠C = 51.75°
__
<em>Check</em>
E = 3x = 38.25, then C+E = 51.75 +38.25 = 90 . . . . as it should
Answer:
if exterior angle is 10 degrees, then interior angle is 180 -10 = 170 deg.
Each trinaglke inside the polygon will be isosceles with two angles of 170/2 - 85 degrees each.
So, angle at centre = 180 -170 = 10 deg.
Ttal angle at centre = 360 deg.
No of sides = 360 /10 = 36 sided polygon.
b) Sum of interior angles is given by (2N-4) Right angles
So: 9900 = (2N-4)x90 = 180N - 360
180N = 9900 +360 = 10260
N = number of sides = 10260 / 180 = 57 sides