Question

solve the problem. if necessary, round to the nearest tenth.
a car dealer advertised a big sale by stretching a string of banners from the top of the building to the edge of the driveway. if the building is 21 m high and the driveway is 43 m from the building, how long is the string of banners?
a 8.0 m
b 47.9 m
c 37.5 m
d 29.7 m

Explanation:

Step1: Apply Pythagorean theorem

The problem forms a right - triangle, where the height of the building \(a = 21m\) and the distance of the driveway from the building \(b=43m\). The length of the string \(c\) (hypotenuse) is found using \(c=\sqrt{a^{2}+b^{2}}\).

$$c=\sqrt{21^{2}+43^{2}}$$

Step2: Calculate \(a^{2}\) and \(b^{2}\)

$$21^{2}=441$$

,

$$43^{2}=1849$$

$$c=\sqrt{441 + 1849}$$

Step3: Sum and take square - root

$$441+1849 = 2290$$

$$c=\sqrt{2290}\approx47.9$$

Answer:

B. \(47.9m\)