Formulas
What is the formula for area of a parallelogram?
A=bh
Area = base(height)
A parallelogram has a base of 6cm and a height of 4 cm, what is the area?
24cm2
The top of a trapezoid is 20cm, the bottom of the trapezoid is 32cm, and it is 16cm tall. What is the area?
A = 1/2(20+32)(16)
A= 1/2(52)(16)
A=416cm2
Find the area of a kite if its diagonals are 5in. and 12 in.
A = 1/2(5)(12)
A = 1/2 (60)
A = 30in2
A circle has a radius of 4.2m. Find the area.
A = pi(4.2)2
A = 55.4m2
What is the formula for area of a triangle?
A=1/2bh
Area = 1/2(base)(height)
A parallelogram has a base of 8cm and a height of 5cm. A student says that HALF of the area is 40cm2. Is this student correct?
No, half of the area is 20cm2
A = 1/2 (7+11)(7)
A = 1/2 (18)(7)
A= 63m2
A kite has a diagonal of 8yd and another diagonal of 10 yards. Find the area of the kite.
A = 1/2 (8)(10)
A = 1/2(80)
A= 40yd2
A circle has a diameter of 14ft. Find the area.
If diameter is 14, radius is 7.
A = pi(7)2
A = 154ft2
What is the formula for area of a trapezoid?
A = 1/2(b1+b2)h
Area = 1/2(base1 + base2)(height)
The area of a parallelogram is 102ft2. The base of the parallelogram is 17ft. How tall is it?
It is 6 feet tall
102/17 = 6
The area of a trapezoid is 77ft2. One base is 8ft and the other base is 14ft. How tall is the trapezoid?
77= 1/2(8+14)(h)
77= 1/2(22)h
77=11h
height = 11ft
Diagonal 1 = 7ft. Diagonal 2= 14ft. Find the area of the kite.
A = 1/2(98)
A = 49ft.2
A circle has a radius of 5cm. The measure of an arc is 63 degrees, find the area of that sector.
A = pi(5)2 x (63/360)
A = 13.7cm2
What is the formula for area of a circle?
A = pi(r)2
No, it is 3cm tall.
21/7= 3
The area of a trapezoid is 132in2. The trapezoid has a base of 7in. and another base of 17in. How tall is the trapezoid?
132 = 1/2(7+17)(h)
132 = 1/2(24)h
h = 11in.
1/2 of diagonal 1= 6cm
1/2 of diagonal 2= 10cm
Find the area of the kite
Diagonals = 12 and 20
A = 1/2(12)(20)
A = 1/2(240)
A = 120cm2
A circle has a radius of 7.5m. The measure of an arc is 45 degrees. Find the area of that sector.
A = pi(7.5)2(45/360)
A = 22m2
What is the formula for area of a kite?
A = 1/2(d1)(d2)
Area = 1/2 (diagonal1)(diagonal2)
A parallelogram has an area of 153ft2. It is 9ft tall, how long is the base of the parallelogram?
17ft
153/9 = 17
A trapezoid has top of 4.4in, a bottom of 6.2in, and a height of 4.6in. Find the area.
A = 1/2(4.4+6.2)(4.6)
A = 1/2 (10.6)(4.6)
A= 24.38in2
1/2 of diagonal 1 = 7.5ft
1/2 of diagonal 2= 9.5ft
Find the area
A = 1/2 (15)(19)
A = 1/2 (285)
A= 142.5ft2
Find the diameter of a circle with an area of 314in2.
314 = pi(r)2
radius is 10 in, so diameter is 20in.