BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

Area of triangle formed by intersections of 3 lines

Expert replies
by gmattesttaker2 » Sat May 03, 2014 10:52 am
Hello,

Can you please assist with this:

What is the area of a triangle created by the intersections of the lines x=4, y=5, and y=−3/4x+20?

OA: 96

x = 4 and y = 5 will intersect at the point (4,5). I am thinking that y = -3/4x + 20 means that the slope m = -3/4 and the y-intercept = 20. I am not sure though how to find out where it will intersect the lines x = 4 and y = 5. Can you please explain it? Thanks a lot.

Regards,
Sri
Join the discussion
Source: — Problem Solving |

by Brent@GMATPrepNow » Sat May 03, 2014 11:44 am
gmattesttaker2 wrote:Hello,

Can you please assist with this:

What is the area of a triangle created by the intersections of the lines x = 4, y = 5, and y= −3/4x + 20?


Let's first sketch the lines x = 4 and y = 5
Image

To find the point where y = (-3/4)x + 20 intersects the line x = 4, replace x with 4 to get: y = (-3/4)4 + 20 = 17
So the point of intersection is (4, 17)

To find the point where y = (-3/4)x + 20 intersects the line y = 5, replace y with 5 to get: 5 = (-3/4)x + 20
When we solve for x, we get x = 20
So the point of intersection is (20, 5)

Add this information to our sketch:
Image

From here, we can determine the length of the right triangle's base and height:
Image

Area = (1/2)(base)(height)
= (1/2)(16)(12)
= 96

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Join the discussion

by gmattesttaker2 » Sat May 03, 2014 11:46 am
Brent@GMATPrepNow wrote:
gmattesttaker2 wrote:Hello,

Can you please assist with this:

What is the area of a triangle created by the intersections of the lines x = 4, y = 5, and y= −3/4x + 20?
Hello Brent,

Thank you very much for your prompt and excellent explanation.

Best Regards,
Sri



Let's first sketch the lines x = 4 and y = 5
Image

To find the point where y = (-3/4)x + 20 intersects the line x = 4, replace x with 4 to get: y = (-3/4)4 + 20 = 17
So the point of intersection is (4, 17)

To find the point where y = (-3/4)x + 20 intersects the line y = 5, replace y with 5 to get: 5 = (-3/4)x + 20
When we solve for x, we get x = 20
So the point of intersection is (20, 5)

Add this information to our sketch:
Image

From here, we can determine the length of the right triangle's base and height:
Image

Area = (1/2)(base)(height)
= (1/2)(16)(12)
= 96

Cheers,
Brent
Join the discussion

by gmattesttaker2 » Sat May 03, 2014 11:58 am
gmattesttaker2 wrote:
Brent@GMATPrepNow wrote:
gmattesttaker2 wrote:Hello,

Can you please assist with this:

What is the area of a triangle created by the intersections of the lines x = 4, y = 5, and y= −3/4x + 20?



Let's first sketch the lines x = 4 and y = 5
Image

To find the point where y = (-3/4)x + 20 intersects the line x = 4, replace x with 4 to get: y = (-3/4)4 + 20 = 17
So the point of intersection is (4, 17)

To find the point where y = (-3/4)x + 20 intersects the line y = 5, replace y with 5 to get: 5 = (-3/4)x + 20
When we solve for x, we get x = 20
So the point of intersection is (20, 5)

Add this information to our sketch:
Image

From here, we can determine the length of the right triangle's base and height:
Image

Area = (1/2)(base)(height)
= (1/2)(16)(12)
= 96

Cheers,
Brent

Hello Brent,

Thank you very much for your prompt and excellent explanation.

Best Regards,
Sri
Join the discussion