Solving Ratio and Proportion Problems with Cross Multiplication

The video tutorial explains how to solve a geometry problem involving two triangles, one larger than the other. It begins by setting up the problem with given dimensions and then defines variables to represent unknowns. Ratios are established between the dimensions of the triangles, and a proportion is solved using cross-multiplication to find the unknown side. The solution is verified by checking the consistency of the ratios, and the tutorial concludes with a confirmation of the correct answer.

What is the height of the first triangle?

• 12 cm

• 8 cm

• 3 cm

• 2 cm

What is the width of the first triangle?

• 12 cm

• 8 cm

• 3 cm

• 2 cm

Tags

CCSS.1.G.A.1

CCSS.2.G.A.1

What is the height of the second triangle?

• 2 cm

• 3 cm

• 8 cm

• 12 cm

What variable is used to represent the width of the second triangle?

• W

• X

• Z

• Y

Tags

CCSS.3.MD.D.8

What is the ratio of height to width for the first triangle?

• 3:8

• 2:3

• 3:2

• 8:3

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

What is the ratio of height to width for the second triangle?

• 8:X

• X:8

• 3:X

• 2:X

Tags

CCSS.6.RP.A.1

CCSS.6.RP.A.2

What is the result of cross-multiplying 2 and X?

• 2X

• 24X

• 3X

• 8X

Tags

CCSS.7.RP.A.3

What is the result of cross-multiplying 3 and 8?

• 32

• 24

• 48

• 16

Tags

CCSS.7.RP.A.3

What is the width of the second triangle after solving the proportion?

• 8 cm

• 10 cm

• 14 cm

• 12 cm

Tags

CCSS.HSG.CO.C.9

How many times greater is the height of the second triangle compared to the first?

• 3 times

• 2 times

• 5 times

• 4 times

Tags

CCSS.4.OA.A.1