Formulas
Write the equation for the three angles inside of a triangle.
a + b + c = 180
89 degrees
One angle of a triangle is 3x, another angles has a measure of 5x and the third angle measures 28 degrees. Write the equation and find the value of x?
3x + 5x + 28 = 180
x = 19
Define circumference.
The distance around the circle, also known as perimeter.
Define area of a circle
The space a circle occupies / takes up / covers
What is the relationship between radius and diameter? Provide 2 formulas.
r = 1/2d
d = 2r
Do the following side lengths create a triangle?
10cm, 12cm, and 25cm
No
A right triangle has an angle of 51 degrees and an angle of 2x + 5. Write the equation and solve for the value of x?
90 + 51 + 2x + 5 = 180
x = 17
What is the circumference of a circle with a diameter of 5m?
15.7m
Find the area of a circle with a 9 cm radius.
A = 254.34 cm
What is the formula to find circumference of a circle? Provide 2 formulas.
c = π d
c = 2 π r
Do the following side lengths create a triangle?
19in, 26in, 40in
Yes
A right triangle has an angle of 20x - 9 and another angle of 10x + 9. What is the value of x?
x = 3
What is the circumference of a circle with a radius of 4.3 cm?
27.004 cm
Find the area of a circle with a diameter of 11 in.
94.985 in
What is the formula to find area of a circle?
A = π r²
A right angle has a measure of 18 degrees. What is the value of the missing angle?
72 degrees
The angles inside a triangle are as follows:
Angle 1 = 9x + 8
Angle 2 = 10x
Angle 3 = 8x + 10
What is the value of x?
x = 6
What is the circumference of a semicircle with a radius of 15.2?
47.728
Find the area of a semicircle with a diameter of 14 km.
76.93 km
What is the formula for the value of pi?
pi = circumference / diameter
An angle in an isosceles triangle has a measure of 74 degrees. What is the measure of the other two congruent angles?
53 degrees
Angles of a triangle are as follows:
Angle A = 3x
Angle B = 41 degrees
Angle C = 5x - 5
Solve for x and find the measure of angle C.
3x + 41 + 5x - 5 = 180
x = 18
Angle C = 85 degrees
Ellen has two pizzas left after a party. One is a whole pizza and the other is a half-eaten pizza. The whole has a radius of 7in. The half-eaten pizza has a diameter of 18in. What is the difference in circumference between the two pizzas?
whole pizza = 43.96 in
half-eaten pizza = 28.26 in
difference = 15.7 in
A circular water sprinkler covers an area of 530.66 yards. What is the radius of the sprinkler?
r = 13 yds