Three math problems with finding area. PLEASE HELP! (Multiple Choice)?

Question

1. Find the area of a parallelogram with a base of 6 cm and a height of 9 cm.

A) 3 sq. cm

B) 15 sq. cm

C) 54 sq. cm

D) 30 sq. cm

2. Find the area of a triangle with a base of 12 m and an altitude of 9 m.

A) 21 sq. m

B) 42 sq. m

C) 54 sq. m

D) 108 sq. m

3. If the diagonals of a rhombus are 8 cm and 15 cm long, find the area of the rhombus.

A) 60 sq. cm

B) 240 sq. cm

C) 120 sq. cm

D) 480 sq. cm

Thanks so much to all who answered in advance!

Answer 1

1. (C) 54 sq. cm

Area of a parallelogram = base length x vertical height

2. (C) 54 sq. cm

Area of a triangle = 0.5 x base x altitude

3. (A) 60 sq. cm

Area of a rhombus = 0.5 x (diagonal1 x diagonal2)

Answer 2

C) 54 sq. m

C) 54 sq. m

A) 60 sq. cm

I did this test two times trust me on these answers

Answer 3

OK

1. Since you have the base and height it's pretty easy b*h

= 54 sq. cm (C)

2. 1/2 b*h = 1/2 (12)(9) = 54 sq. cm (C)

3. Diagnals of a rhomnus are bisected at the midpoint.  So you have 4 congruent triangles eas 1/2(1/2(8)(1/2(15)) = 1/2(4)(7.5) = 1/2 (30) = 15

15*4 = 60 sq. cm. (A)

Hope that helps.  

Answer 4

A = bh = 6*9 = 54 cm^2

A = bh/2 = 12*9/2 = 54 m^2

A = d1d2/2 = 8*15/2 = 60 cm^2

Answer 5

Well, a parallelogram's area is found the same way as a rectangle, as that's basically all it is, except the sides are slanted (although technically, a rectangle is one too, just with no slant at all).

Triangles if I remember correctly are 1/2(base*height).

And rhombus is both diagonals multiplied together, divided by 2.

Answer 6

1)  C    finding the area of a parrelelagram is the same as finding the area of a rectangle so it's 6x9 which is 54

2)  C    the area of a triangle is Area=half of base times altitude 9 x 12 is 108. 108 over 2 is 54

3)  C    the rhombus is basically the same as a parrelagram which is like a rectangle so 8 x 15 = 120