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30 votes
The base of triangle exceeds the height by 4cm if the area is 30cm² then find the langth of base & hight of triangle​

User Emdee
by
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1 Answer

23 votes
23 votes

Answer:

Base = 10 cm

Height = 6 cm

Explanation:

Here is the formula for the area of a triangle.


A=(bh)/(2)

We are given


A=30


b=h+4

Replace all occurrences of
b with
h+4 in each equation.


(h+4)*(h)/(2) =30

Apply the distributive property.


h((h)/(2))+4((h)/(2))=30


(h*h)/(2)+4((h)/(2))=30

Use the power rule to combine exponents.


(h^2)/(2)+4((h)/(2))=30

Factor 2 out of 4 .


(h^2)/(2)+2(2)((h)/(2))=30

Cancel the common factor.


(h^2)/(2)+2h=30

Solve for h.

Multiply each term in
(h^2)/(2)+2h=30 by 2 to eliminate the fractions.


(h^2)/(2)*2+2h*2=30*2

Simplify each term.

Cancel the common factor of 2.


h^2+2h*2=30*2


h^2+4h=60

Subtract 60 from both sides of the equation.


h^2+4h-60=0

Factor using the AC method.

Consider the form
x^2+bx+c . Find a pair of integers whose product is
c and whose sum is
b . In this case, whose product is − 60 and whose sum is 4 .

−6, 10

Write the factored form using these integers.


(h-6)(h+10)=0

Set
h-6 equal to 0 and solve for h.

Then add 6 to both sides of the equation.


h-6=0\\h=6

Set
h+10 equal to 0 and solve for h.

Then subtract 10 from both sides of the equation.


h+10=0\\h=-10

The final solution is all the values that make
(h-6)(h+10)=0 true.


h=6,-10

Given
b=h+4

Replace all occurrences of h with 6 in each equation.


b=6+4\\b=10\\h=6

User Aviomaksim
by
3.6k points